Happy birthday, Carl! Here's half a million bucks

Activist investor Carl Icahn turns 80 on Tuesday, and he's got a few hundred thousand things to celebrate.

Specifically, $581,793, according to CNBC.com calculations.

That's how much Icahn has made — on average — every single day he's been alive. That's a pretty hefty birthday present. Of course, he wasn't earning that much when he was born in 1936, but he's more than made up for it since. He's amassed a fortune of $17 billion, according to the most recent estimates from Forbes.

Net worth (billions)
Avg. daily earnings (thousands)
Carl Icahn $17.0 80 $581.8
Michael Milken $2.5 69 $98.3
Leon Black $4.5 64 $190.9
Mark Zuckerberg $44.6 31 $3,844.8
Warren Buffett $60.8 85 $1,947.7
Bill Gates $75.1 60 $3,409.6
Michael Bloomberg $39.9 74 $1,476.1
Jeff Bezos $45.2 52 $2,375.4
Larry Page $35.4 42 $2,259.5
Steve Schwarzman $9.7 69 $384.9
Henry Kravis $4.2 72 $159.5

Source: Forbes; CNBC calculations

The billionaire activist investor celebrated the big 8-0 with a steak dinner at Mastro's Steakhouse in midtown Manhattan last week, according to the New York Post. In attendance were a crowd of private equity impresarios: Michael Milken, Apollo's Leon Black, Howard Lorber, Rich Handler, Andrew Whittaker and Bennett LeBow.

The group spent the evening joshing each other, imbibing red wine and eventually "depleted the restaurant's caviar supply," according to an anonymous source cited in the Post's Page Six gossip column. Icahn did not immediately respond to a CNBC.com request for comment.

It's understandable. Those guys are the titans of private equity and both Milken and Black are also on Forbes' list of billionaires. But they're small fries compared to Icahn. Black, at 64, has averaged around $190,000 per day he's been alive. Milken, who turns 69 later this year, has pulled in $98,313 on average.

But it's not all a happy birthday for Carl. His public-facing investment firm, Icahn Enterprises, has lost 53 percent in value over the past 12 months amid a series of poor investments in energy. On the other hand, Icahn scored last week when American International Group agreed to put one of his analysts on its board. He's been pushing the insurance giant to slim down in recent months.

Icahn has been instrumental in a number of corporate spin-offs over the years and his firm's success often comes in years with a lot of big deals.

Clearly, Icahn didn't make that $17 billion just from riding the market. You'd have to have invested $164 million in the Dow 30 the day Icahn was born to have generated that kind of return today.

Icahn and his private equity friends have done pretty well for themselves per day, but it's nothing compared to some of the tech and media businessmen out there. Amazon's Jeff Bezos, for example, has made more than $2.4 million for every day he's been alive. Warren Buffett, the 85-year-old Oracle of Omaha has made more than $1.9 million.

Facebook's Mark Zuckerberg, who will be 33 in May, has made a whopping $3.8 million per day.