Poor Larry Page and Mark Zuckerberg. They're worth billions of dollars, and that makes life hard.

Actually, it kind of does, and Y Combinator co-founder Paul Graham explains why. Graham's startup accelerator program yielded a few billionaire founders of its own, including Dropbox's Drew Houston and the founders of Airbnb.

Graham points out that Google and Facebook run Page and Zuckerberg as much as they run their companies. They can never enjoy regular activities or do things spontaneously the way the rest of us can.

"Mark Zuckerberg will never get to bum around a foreign country," Graham writes. "He can do other things most people can't, like charter jets to fly him to foreign countries. But success has taken a lot of the serendipity out of his life."

What adds to the stress: billionaires can never publicly complain about how tough their money-filled lives sometimes are, because everyone else will freak out.

In a Stanford talk about how tough it is to be an entrepreneur, Graham says how all-consuming running a startup — even once it becomes a multi-billion-dollar company, can be. Here's an excerpt:

Larry Page may seem to have an enviable life, but there are aspects of it that are unenviable. Basically at 25 he started running as fast as he could and it must seem to him that he hasn't stopped to catch his breath since. Every day new shit happens in the Google empire that only the CEO can deal with, and he, as CEO, has to deal with it.

If he goes on vacation for even a week, a whole week's backlog of shit accumulates. And he has to bear this uncomplainingly, partly because as the company's daddy he can never show fear or weakness, and partly because billionaires get less than zero sympathy if they talk about having difficult lives. Which has the strange side effect that the difficulty of being a successful startup founder is concealed from almost everyone except those who've done it.

...Mark Zuckerberg will never get to bum around a foreign country. He can do other things most people can't, like charter jets to fly him to foreign countries. But success has taken a lot of the serendipity out of his life. Facebook is running him as much as he's running Facebook. And while it can be very cool to be in the grip of a project you consider your life's work, there are advantages to serendipity too, especially early in life. Among other things it gives you more options to choose your life's work from.

SEE ALSO: Startup God Paul Graham Has 6 Pieces Of Advice For Anyone Thinking About Doing Their Own Company

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Shares of Chinese property Agile Property Holdings fell more than 17% on Monday after trading in the shares re-opened after the company canceled a proposed $350 million share offering. 

Trading in the stock had been halted since October 3, pending news about the share offering, which was supposed to take place last Friday.

The halt in shares and the canceling of the offering also came amid rumors that the company's chairman, Chen Zhoulin, had gone missing; Zhoulin and his family are the company's controlling shareholders. 

On Monday, Zhoulin was placed under custody by Chinese prosecutors and accused of money laundering, according to a Bloomberg News report on Monday. 

Here's the chart of Monday trading in Agile shares in Hong Kong, which were down as much as 31% at one point before closing with losses of 17%. 

SEE ALSO: 30 Stocks Traders Are Shorting Like Crazy

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According to Credit Suisse's 2014 Global Wealth Report, there are 128,200 ultra-high net worth (UHNW) individuals in the world. These are the folks whose net worth exceeds $50 million.

That's up from 98,700 a year ago.

"The number of HNW and UHNW individuals has grown rapidly in recent years, reinforcing the perception that the very wealthy have benefitted most in the favorable economic climate," Credit Suisse analysts write.

"Between 2008 and mid-2014, mean wealth per adult grew by 26%; but the same period saw a 54% rise in the number of millionaires, a 106% increase in the number with wealth above $100 million, and more than double the number of billionaires."

So, where can we find the world's 0.0017994134%?*

Most of them can be found in the US. Here's Credit Suisse:

"Among individual countries, the United States leads by a huge margin with 62,800 UHNW adults, equivalent to 49% of the group total. This represents an increase of 9,500 compared to mid-2013, an astonishing rise for a single year – more than the total number of UHNW residents in China, which occupies second place with 7,600 residents (6% of the global total). the United Kingdom gained the second largest number of UHNW individuals (up 1,300 to 4,700) consolidating fourth place, behind Germany (5,500), but ahead of France (4,100). Taiwan (2,000) and Korea (1,900) each added about 550, while Brazil (1,900), Canada (2600) and Hong Kong (1,500) gained 200 apiece. the numbers for Russia (2,800) and India (1,800) were almost unchanged."

"[L]ittle can be deduced about inequality trends from the fact that the number of millionaires and billionaires is growing faster than average wealth," the analysts argue. "[T]his is almost certain to hap pen when wealth is growing, regardless of whether inequality is rising or falling."

*This percentage is based on the World Bank's 2013 world population estimate of 7,124,544,000.

SEE ALSO: 19 Of The Most Expensive Substances In The World

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Facebook COO Sheryl Sandberg has offloaded her seven-bedroom home in ritzy Atherton, California, Trulia reports. 

According to property records, the couple sold the property for $9.25 million in September. They recently upgraded to a sleek contemporary home in nearby Menlo Park, closer to Facebook headquarters. 

She purchased the 11,430-square-foot estate with her husband, SurveyMonkey CEO David Goldberg, for $7.995 million in 2004, when she was still a top executive at Google. 

The home is located in Atherton, the Silicon Valley town that was recently named the most expensive zip code in the country.

It has three stories and is situated at the end of a gated driveway.

There's a total of seven bedrooms and nine bathrooms, plus a home theater, recreation room, wine cellar, and fitness center with a sauna.

It also has an expansive backyard.

There's a gorgeous view of the surrounding woods from the back patio.

There's also a guest house with a full kitchen and bathroom.

SEE ALSO: Take A Tour Of Mark Zuckerberg's Gigantic New $100 Million Property In Hawaii

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Billionaire energy mogul T. Boone Pickens didn't earn his fortune without the help of others. Most notably, he finds that some of his best advice came from his father. 

Produced by: Justin Gmoser; Reporter: Julia La Roche

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Long-term residents of the so-called Billionaire's Row are increasingly leaving the stretch as rapid, high-end development is transforming their neighborhood.

In recent months, resales of condos and co-ops are up 83.9% in the second quarter, according to the New York Daily News.

"This is a case of a rising tide lifting all boats,” Alan Lightfeldt, a data scientist at StreetEasy, told the newspaper. “There’s certainly more interest in properties on the 57th St. corridor, which used to melt into the rest of Midtown. Now, it’s quite a powerful address."

Asking prices in the new towers on 57th Street, such as One57 at 157 West 57th Street, are soaring, reaching $6,000 per square foot. Other new developments include 111 West 57th Street, 227 West 57th Street and the Robert A.M. Stern-designed 220 Central Park South.

Apartments in older buildings on the same street are much cheaper, the paper reported. Units at the Osborne and Alwyn co-op buildings, according to the newspaper, are below $2 million.

[NYDN] 

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What's the difference between someone who makes $1 million and someone who makes $1 billion?

According to John Sviokla and Mitch Cohen, authors of "The Self-Made Billionaire Effect: How Extreme Producers Create Massive Value," it comes down to what the authors call "habits of mind."

Sviokla, the head of global thought leadership at Pricewaterhouse Coopers and a former Harvard Business School professor, and Cohen, a vice chairman at PwC, conducted a study of 120 self-made billionaires, randomly chosen from a pool of 600 global candidates.

They selected subjects who created $1 billion of wealth through "entrepreneurial activity," operated in regulated and somewhat transparent markets, and who didn't inherit the bulk of their wealth (although they did qualify if they grew their inherited wealth by 100 times or more). They then learned everything they could about the finalists.

The authors write that while they expected to find commonality among the billionaires' external circumstances, be it disadvantaged backgrounds or existential challenges, the common thread they found among the billionaires was internal: habits of mind.

Specifically, the billionaires are largely able to achieve what the authors refer to as a "duality of mind" between imagination and judgment — the ability to imagine something greater while seeing existing things truly as they are. Sviokla and Cohen write:

These dual habits of mind and action enable them to function as what we term Producers: They envision something new, bring together the people and the resources to create it, and sell it to customers who didn't know they needed it.

The opposite of this is what the authors term Performers: people who excel at operating within our existing systems and structures. Performers can be very successful, but there's a drawback to their strengths:

That single-minded talent for reaching otherworldly heights within a defined environment — so necessary in many aspects of business — reinforces function-driven systems that discourage the integrated habits of mind and action necessary for Producers.

There is, however, a ray of hope for those of us who recognize ourselves as Performers. Sviokla and Cohen found that while many of the billionaires they studied appeared to have an inherent Producer mindset, it's their practice and cultivation of needed habits of mind that make them stand out in the crowd.

And, they write, anyone can change and improve their habits of mind. There's hope for us yet.

SEE ALSO: What The Middle Class Doesn't Understand About Rich People

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Earning the title of CEO is a huge accomplishment. Doing it eight times over is almost unheard of.

Almost.

Fred Mouawad, the French-Lebanese serial entrepreneur and heir to the world-renowned Mouawad diamond jewelry company, has managed to do just that by the age of 45.

Mouawad, who is worth an estimated $1.1 billion, according to research firm Wealth-X, first became a chief executive just after graduating from Harvard Business School in 1994 when he founded Synergia One Group.

He has since founded and become CEO of six more companies — including tech, consulting, food, retail, and media businesses — and also runs the 125-year-old family business, Mouawad Jewelry (the only company of which he's chief executive that he didn't also found). 

Mouawad's most recent venture is Taskworld, an online task and project management platform that allows teams to collaborate while tracking individual performance.

"As a serial entrepreneur I have spent a lot of time building businesses from scratch," Mouawad tells Business Insider, "learning all there is to learn about the business, building a team, and slowly moving myself out of a job. As my portfolio is growing, I have the dual responsibility of incubating a new venture while also overseeing the other companies in the portfolio." 

Here are five of the most important things Mouawad says he's learned throughout his career as an eight-time CEO:

1. Know thyself.

Mouawad explains that it's extremely important for leaders to be self-aware, to constantly reflect, and to figure out how to improve their leadership. "We all have blind spots, so it's important to constantly seek and provide feedback in a respectful and safe environment to drive continuous improvements." Once leaders understand themselves, they can figure out what team to surround themselves with to maximize value. 

2. You are only as good as the people around you.

"The best teams usually win," he says. "It's all about having the right people, in the right positions, and with the right motivation to fulfill the organization's mission and goals." 

3. Connect the dots between the internal and external worlds.  

Too often leaders are either too internally or externally focused, Mouawad explains. "The art of balancing the two is critical in order to find the right alignment between the organization and the marketplace."

4. Developing a mental framework is crucial to success.

Mouawad says he has basically approached every business with the same mental framework — and at least some of his success can be attributed to it.

"I first define where the business should be in the future so it is customer-centric and competitive. I then focus on building the right team with the right attitude, skills, and will to succeed; I make sure we have the right capital; and then I focus on building the culture that's required to win at the game we choose to play."

5. Monitor your company's culture, and know it will change.   

Culture is the most difficult and dynamic aspect of building a business, he says. "It morphs all the time based on the people in leadership positions. It has to be constantly monitored, but once you get it right, it becomes a powerful driver of execution."

Want your business advice featured in Instant MBA? Submit your tips to tipoftheday@businessinsider.com. Be sure to include your name, your job title, and a photo of yourself in your email.

SEE ALSO: Here's What 10 Super-Successful People Would Change About The World

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There are 2,325 billionaires on the earth.

And they control 4% of the world's wealth.

According to a new report from the research firm Wealth-X, about 13% of billionaires inherited their fortune, 27% became billionaires from re-investing inherited wealth, and a full 60% of billionaires made their money themselves.

Let's drill into how they made all that cash. 

"Opportunities for significant wealth gains can be found across most, if not all industries," the report reads, "but certain industries have been particularly important sources of billionaire wealth generation." 

Here are the top five: 

Unsurprisingly, most billionaires make their dough in finance. 

The fascinating trend here is just how much wealth industrial conglomerates are creating, which Wealth-X chalks up to globalization. 

"Billionaires are increasingly gravitating towards diversified business ventures such as industrial conglomerates, especially in emerging markets," the reports says. "For Latin America and the Caribbean, Asia, Africa, and the Middle East, the largest proportion of new billionaires made their fortunes in industrial conglomerates." 

The takeaway: If you want to achieve ridiculous wealth, go to Wall Street — or the developing world. 

And attending one of these schools can't hurt, either. 

NOW WATCH: The Most Important Thing I Learned About Business From Hugh Hefner

SEE ALSO: The World's 2,325 Billionaires Have These 14 Traits In Common

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The private jets of the ultra-wealthy and ultra-famous are impressive.

But they're also important.

You need to way to get to that third, fourth, or fifth residence. And don't forget about the private island.

The best way to travel to an exclusive beach paradises is on your own plane.

Of course, not everyone on this list has an island, but you might say that for some, these jets are islands unto themselves.

[An earlier version of this article was written by Matthew Kassel.]

Russian billionaire Roman Abramovich's Boeing 767-33A, usually docked at Luton Airport north of London, is reportedly decorated with a gold interior.

Source: newzglobe.com

Technically, it belongs to the people of the USA. But President Obama's ride, Air Force One, ferries the Commander-in-Chief in style. It's a Boeing 747-200B and comes equipped with a self-contained baggage loader and the ability to re-fuel in flight.

Source: newzglobe.com

Gautam Singhania, chairman of the Raymond Group, owns this Challenger jet featuring an advanced Collins ProLine IV EFIS avionics system.

Source: Luxpresso

Let's agree right off the bat that $25 million is a lot of money.

Sure, to paraphrase Chris Rock (NSFW), if Bill Gates woke up tomorrow with a net worth of $25 million, he'd jump out a window.

But to the vast majority of us, it's a huge sum, more than enough to make some dreams come true. If money can't buy happiness, $25 million should at least be enough for a down payment on contentment — and to generate some envy on the part of us without eight figures in assets.

Well, get ready to get jealous, if only for a moment. The number of American households with a net worth of $25 million or more — excluding their home — reached a new record last year, according to a recent report by wealth management research provider Spectrem Group.

Related: 10 Worst States for Surviving a Financial Disaster

Yet the same survey found that those wealthy Americans still have plenty of financial concerns. Actually, they sound fairly miserable…and that's in a survey taken well before the recent stock market tumble.

They may travel more, go to ballgames or concerts, or buy nice jewelry, but 70% of those surveyed said they get more satisfaction out of saving and investing their money than from spending it. More than half said they worry about the next generation wasting the money they inherit. And almost a quarter (23%) said they worry "constantly"— constantly — about their financial situation.

Many others worry less about their own financial situation than about the legacy they'll leave their children and grandchildren, including making sure that the kids develop a respectable work ethic.

Related: Are 401(k) Plans Setting Up Millennials for Pain?

Maybe that's all reflective of who these people are, or aren't. By and large, the wealthy Americans surveyed by Spectrem aren't lounging around in their mansions counting their cash.

Their average age is 58, and nearly 60% are still working, and another 20% are only semi-retired. Roughly nine out of 10 wealthy households attribute their success to hard work, and about eight in 10 credit education, while just over half credit "luck" or "being in the right place at the right time." Most are entrepreneurs and business owners (22%), professionals (22%), or corporate executives (15%).

"Additionally," Spectrem said in its press release, "the wealthiest of these 'one percenters' now consist of working households with two income wage earners under age 55, nearly three-quarters of whom work more than 40 hours per week." Plus, those still working likely plan on continuing to work as long as they can.

So maybe, just maybe, being wealthy isn't all it's cracked up to be. Often enough, it apparently still means long hours and more than a few financial headaches. Then again, having $25 million in assets sure could make our current long hours and financial headaches that much easier to bear.

SEE ALSO: Here's Exactly What To Say When Your Kid Asks, 'Are We Rich?'

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The University of Pennsylvania has produced more billionaire undergraduate alumni than any other school in the world, according to a recent report from Wealth-X.

25 current billionaires received their bachelor's degrees at Penn, the most of any school on Wealth-X's list. The only other colleges to produce similar numbers were Harvard University — with 22 undergrad alum billionaires — and Yale University — with 20.

Although UPenn is home to the Wharton School, which is considered to be a top business school for both undergraduate and graduate students, Wealth-X president David Friedman told Business Insider that the school's powerhouse reputation doesn't have a huge impact on its ultra-wealthy alumni base.

"On the surface I think that's a contributing factor, but it's definitely not a core driver" of UPenn's high number of billionaires, Friedman said.

Rather, Friedman noted, UPenn's billionaires represent successes in an array of fields, which suggests that the university isn't focused entirely on channeling students into financial services or technology.

To this point, Friedman mentioned three billionaires who got their undergraduate degrees at UPenn — Tory Burch, Elon Musk, and Steven Cohen — who made their money in fashion, technology, and finance, respectively.

Other UPenn billionaires include Donald Trump, Charles Butt, Jon Huntsman Sr., Ronald Perelman, George Lindemann, and Leonard Lauder.

Whatever you attend school, Friedman emphasized the importance of actually finishing college and getting a bachelor's degree.

"There's this myth that if you want to be a tech billionaire, you drop out of school," Friedman said. "This kind of dismantles that myth. It's about people, relationships, networks."

Additionally, Friedman highlighted something that he believes is not being discussed enough on college campuses — encouraging students to take a risk and fail.

"Most entrepreneurs have failed multiple times ... I think it's a very critical element, because emotional endurance is one of the most critical attributes for entrepreneurs," Friedman said.

Here are the 20 universities with the most billionaire undergraduate alumni and how many alumni they have, via Wealth-X:

1. University of Pennsylvania — 25

2. Harvard University — 22

3. Yale University — 20

4. University of Southern California — 16

5. Cornell University — 14

5. Princeton University — 14

5. Stanford University — 14

8. University of California, Berkeley — 12

8. University of Mumbai (India) — 12

10. London School of Economics (United Kingdom) — 11

10. Lomonosov Moscow State University (Russia) — 11

12. Dartmouth College — 10

12. University of Michigan — 10

12. University of Texas — 10

15. Duke University — 9

15. New York University — 9

17. Brown University — 8

17. Columbia University — 8

19. Massachusetts Institute of Technology — 7

20. Eth Zurich (Switzerland) — 6

SEE ALSO: The 20 Universities That Have Produced The Most Billionaires

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Everyone needs to take a vacation every once in awhile. 

But "vacation" means something a little different when you're a tech millionaire or billionaire. 

From massive island retreats to private superyachts, these tech executives' second homes take luxury vacations to the next level. 

Facebook billionaire Mark Zuckerberg recently bought a 750-acre property on the North Shore of Kauai. He paid a reported $100 million for the property, which includes a white-sand beach and former sugarcane plantation.

Source: Forbes

When Microsoft billionaire Paul Allen isn't cruising the high seas on one of his superyachts, he can relax at one of his many luxurious retreats. In addition to an island in Washington and a beachfront Hawaiian estate, Allen owns a hilltop mansion on the Côte d'Azur called the Villa Maryland. He employs a staff of 12 and counts Bono and Andrew Lloyd Webber as neighbors.

Source: Curbed

Salesforce CEO Marc Benioff loves all things Hawaii. He wears Hawaiian shirts to work and even named his dog "Koa," after a type of Hawaiian tree. He also owns a 5-acre estate on the Big Island, which he purchased for $12.5 million in 2000.

Source: Wall Street Journal, Honolulu Magazine

Billionaire energy mogul T. Boone Pickens didn't earn his fortune without the help of others. Most notably, he finds that some of his best advice came from his father. 

Produced by: Justin Gmoser; Reporter: Julia La Roche

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To say that Warren Buffett has a deep understanding of business — training himself with critical thinking exercises and a rigorous reading program— is a bit of an understatement.

The proof is in the profits. His Berkshire Hathaway holding company has amassed a market cap over $300 billion. His personal fortune is upwards of $68 billion.

So when he starts doling out career advice, we listen. 

In a series on Fortune in which CEOs offer their best advice, the Sage of Omaha counseled young women on how to advance their careers. 

But we think it applies to everybody. 

"You do the same thing a male will do," Buffett said. "You follow your passions. You find something you love."

By doing that, the logic goes, you'll bring more energy to your work than everybody else. 

"The truth is, so few people really jump on their jobs, you really will stand out more than you think," Buffett said. "You will get noticed if you really go for it.”

In this way, Buffett's advice parallels what comedian Steve Martin says to people who want to break into show business: "Be so good they can't ignore you."

For five strategies for doing just that, go here. 

NOW WATCH: 11 Words You're Mispronouncing All The Time

SEE ALSO: 9 Books Billionaire Warren Buffett Thinks Everyone Should Read

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At a spending rate of $1 million a day, most people would blow through their entire life savings in, well, a day.

But for billionaire Bill Gates, it would take 218 years to spend his approximate $79 billion fortune at this rate, according to new research from Oxfam that was recently highlighted by The Guardian. That's about three Ferraris a day. 

It would take Mexico's Carlos Slim, the world's richest man, even longer at 220 years. Warren Buffett could get through his fortune slightly faster, but it would still take 169 years to clear his bank account. 

While few could keep up with these hypothetical spending patterns, more people than ever can call themselves billionaires these days. In fact, the number of billionaires in the world has more than doubled since the recession, rising from 793 in March 2009 to 1,645 in March 2014, Oxfam reports. 

And wealth proves to be the gift that keeps on giving — billionaires average a 5.3% return on wealth, compared to the 1.95% return rate for the ordinary person. This means Gates makes an approximate $11.5 million a day from interest. 

When comparing this extreme wealth to those on the other side of the economic spectrum, however, the report found some startling inequalities. Namely, the 85 richest people in the world have a combined net worth equal to the poorest half of the entire global population. 

But Gates and Buffett aren't looking for ways to idly blow cash. Rather, both billionaires are known for their charitable ways. Gates runs the Bill & Melinda Gates Foundation, which received nearly $3 billion from Buffett alone in 2014. 

SEE ALSO: 9 Books Bill Gates Thinks Everyone Should Read

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Argentine bond investors are still waiting to get paid — and they're starting to get restless.

After all, if this summer's technical default didn't end the stalemate between Argentina and its holdout hedge fund creditors, what will?

The question remains uncertain (and investors hate uncertainty, obviously), so bondholders of all stripes — those who took haircuts on Argentine sovereign debt dating to the country's 2001 default, and those who did not — are working on more creative ways to recover their money.

In the latest twist of all the many twists, legendary investor George Soros and Hayman Capital's Kyle Bass have both filed suit with a UK judge, asking that he release $282 million worth of interest payments on their investment in the country, according to Bloomberg's Kit Chellel.

That payment has been held up by the fact that a US court ruled that bondholders who did restructure their debt (like Bass and Soros) cannot be paid until bondholders who did not restructure (like hedge fund manager Paul Singer) are also paid.

That ruling is what tipped Argentina into default on July 30. When Buenos Aires tried to make a payment to exchange bondholders and not the holdouts, that payment was stopped by a US court.

Since then, the country has made attempts to change the jurisdiction of the bonds from New York City to Buenos Aires, and has tried to change the custodial bank in charge of payment distribution too.

So far, though, investors have not gotten paid.

Now Soros, Bass, and a few others are arguing that they are "innocent third parties" in this whole debacle and shouldn't be punished for Argentina's holdout spat.

Meanwhile, they also argue, what's an English court doing upholding a US court order anyway?

Argentina's president, Cristina Fernandez de Kirchner, met with George Soros in New York City in September. They discussed Argentina's energy sector. It's got a lot of promise because of the country's large quantities of natural gas, but its development requires investment. And that investment isn't coming in full until this whole debt issue is cleared up.

So there's that.

Another powerful player has also come into the game — a new holdout with more at stake than Paul Singer. Billionaire Kenneth Darth owns $595 million worth of defaulted Argentine bonds to Singer’s $503 million. 

Last week Dart asked a New York Judge to give his claim the same treatment as Paul Singer's.

According to BloombergBusinessweek's Sheelah Kolhatkar, this could be very costly for Argentina:

In addition to Dart, there are approximately $2.4 billion worth of bonds out there that are governed by New York law and in the hands of other holdout investors. The minute Argentina settles with Singer’s group and the bondholder payments are allowed to flow through, all the other holdouts will likely rush forward to Judge Thomas Griesa’s court, demanding the same legal rulings and the same terms, which could block the payments again. 

That would mean that even after Argentina paid the Paul Singer and his company (The Gang of Five, as they're called) the country would still be in default until it paid out the other holdouts.

This is what happens when you put things off.

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Elon Musk, billionaire founder of SpaceX, Tesla, and PayPal, leads a pretty amazing life. 

In January 2013, he spent $17 million on a 20,248-square-foot mansion in Los Angeles' Bel Air neighborhood. He and his five sons had lived in the house for three years, which Musk rented before he felt financially secure enough to buy. 

The home, which has seven bedrooms, a giant screening room, a pool, and a tennis court, is what you would expect from a man worth $8.6 billion.

In November of 2013, Musk paid $6.75 million for a ranch home located across the street from the mansion. No word on whether he plans to demolish the small house to combine the two homes into an even bigger estate.

Musk's house is situated on a hilltop 1.66-acre plot in Los Angeles' ritzy Bel Air enclave.

It overlooks the exclusive Bel Air Country Club.

The house is enormous, with 20,248 square feet of space divided into different wings.

Alwaleed Bin Talal, the Saudi prince who is suing Forbes for defamation after a dispute over his net worth, has already spent £1.4 million ($2.2 million) on legal fees, according to the FT.

The self-proclaimed Warren Buffet of Saudi Arabia cut ties with Forbes last year after they released their 2013 billionaires ranking and listed him at $20bn. He claims he was worth $29.6bn.

But in a preliminary hearing at London's High Court on Tuesday, Alwaleed's lawyer said that his billionaire ranking had nothing to do with the lawsuit.

Instead, Alwaleed is suing the publication for defamation over allegations that he manipulated the share price of his investment fund, Kingdom Holding Company, and for claiming that he purposefully defaulted on an Airbus 380 payment.

(Buying and refurbishing commercial airplanes is a bit of a hobby for the Prince.)

Forbes writer Kerry Dolan said Alwaleed called her at home after the 2013 list was released and pleaded with her, asking, "'What do you want?'"

The FT said the libel trial could begin as soon as next year.

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With a net worth of $81.5 billion, Microsoft cofounder Bill Gates is the richest man in America. 

It shouldn't be too surprising that one of the wealthiest people in the world also has an insanely extravagant home. 

It took Gates seven years and $63 million to build his Medina, Washington estate, named Xanadu 2.0 after the fictional home of "Citizen Kane"'s Charles Foster Kane. 

At 66,000 square feet, the home is absolutely massive, and it's filled with high-tech details.

We've rounded up some of Xanadu 2.0's most over-the-top features here.  

1. It's worth at least $123 million.

According to the King County public assessor's office, the property is worth $123.54 million as of this year. Gates purchased the lot for $2 million in 1988.

He reportedly pays around $1 million in property taxes each year.

2. Half a million board-feet of lumber was needed to complete the project.

The house was built with 500-year-old Douglas fir trees. 300 construction workers labored on the home — 100 of whom were electricians.

3. A high-tech sensor system helps guests monitor a room's climate and lighting.

When guests arrive, they're given a pin that interacts with sensors located all over the house. Guests enter their temperature and lighting preferences so that the settings change as they move throughout the home. Speakers hidden behind wallpaper allows music to follow you from room to room.

4. The house uses its natural surroundings to reduce heat loss. 

Xanadu 2.0 is an "earth-sheltered" house, meaning that it's built into its surroundings to regulate temperature more efficiently.

5. You can change the artwork on the walls with just the touch of a button. 

$80,000 worth of computer screens are situated around the house. Anyone can make the screens display their favorite paintings or photographs, which are stored on storage devices worth $150,000.

6. The pool also has its own underwater music system.

The 60-foot pool is located in its own separate, 3,900-square-foot building. People in the pool could swim underneath a glass wall to come up to a terrace area on the outside.

There's also a locker room with four showers and two baths.

7. There's a trampoline room with a 20-foot ceiling.

No word on how big the trampoline itself is, but we can imagine it would be a fun alternative to your standard exercise routine.

The exercise facilities total 2,500 square feet and also include a sauna, steam room, and separate men's and women's locker rooms.

8. An enormous reception hall could accommodate up to 200 guests. 

The 2,300-square-foot hall could seat up to 150 people for a dinner party, or 200 people standing up at a cocktail event. A six-foot-wide limestone fireplace dominates one wall, while another wall has a 22-foot-wide video screen. 

9. The house has 24 bathrooms, 10 of which are full baths. 

Those bathrooms would definitely be useful if Gates were throwing such a big party. Otherwise, it seems a little over-the-top. 

10. There's a total of six kitchens. 

They're situated at different parts of the house so staff can be ready for any event. 

11. An enormous library houses a manuscript Gates paid more than $30 million for.

The 2,100-square-foot library has a domed roof and two secret bookcases, including one that reveals a hidden bar. On the ceiling you'll find a quote from "The Great Gatsby" that reads: "He had come a long way to this blue lawn, and his dream must have seemed so close that he could hardly fail to grasp it."

The library is home to the Codex Leicester, a 16-century Leonardo da Vinci manuscript that Gates bought at auction for $30.8 million in 1994.

12. The home theatre can accommodate 20 guests in plush seats.

It's designed in an Art Deco style, with comfortable arm chairs, couches, and even a popcorn machine for snacking. 

13. An existing home was removed by barge to make room for a separate activities building.

The 900-square-foot building sits next to Gates' sport court, putting green, and boat docks. 

14. The guest house is just as high-tech as the main house.

According to US News, the 1,900-square-foot guest house was the first building to be completed on the property. The house — which has its own bedroom and bathroom — was meant to be a test of the technology that would eventually be used in the main house. 

Gates wrote much of "The Road Ahead" here. 

15. All together, Gates' garages can accommodate up to 23 cars. 

There are several different garages located at different points around the property. The most interesting one, however, is an underground cave made out of concrete and stainless steel. That garage alone can park 10 cars. Some of the concrete was purposely broken to give it a rough, "deconstructivist" look. 

16. Gates has a favorite tree, and it's monitored electronically 24 hours a day. 

He reportedly became fond of a 40-year-old maple tree that grew close to the home's driveway. It's monitored by computer, and if at any point it becomes too dry, water is automatically pumped into it.

17. An artificial stream is kept stocked with fish.

The stream and wetland estuary were created to solve any problems with runoff that the property's large walls might have created. The water is kept stocked with salmon and sea-run cutthroat trout. 

18. The sand on Gates' beach is imported from the Caribbean.

The lakefront shore contains sand that's delivered in large quantities by a barge from St. Lucia each year.

19. Someone once paid $35,000 just to tour it.

Microsoft holds an auction each year, where employees donate products and services to be bid on. Proceeds go to the company's charitable fund.

Gates has donated private tours of Xanadu 2.0 in the past. According to the Puget Sound Business Journal, a Microsoft employee once won the tour with a bid of $35,000. 

SEE ALSO: Take A Tour Of Bill Gates' New 228-Acre Ranch, Complete With A Horse-Racing Track

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