That's what Apple is worth- it has a market cap (price*shares outstanding) of $515 billion as we go to press. That's over a $100B more than Exxon, the runner up in market cap.
Strangely, Apple isn't overpriced. It earned just under 33 billion dollars last year, giving it a modest price-to-earnings ratio of 15.72. That PE ratio is normal for the computer industry, and if you think Apple's prospects with its iPhones and iPads and other iCandy is better than those mere mortals in their wake, them Apples might be a steal at a new record of $552 a share.
A stock split might be an order, but with odd lot costs being a lot less than in the bad old days, that might not be as much as an issue as it used to be.