Apple is snapping up shares of Apple as fast as it can – updated by Philip Elmer-DeWitt @FortuneMagazine July 25, 2013, 9:02 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons FORTUNE — Armchair CEOs, eyeing Apple’s AAPL growing mountain of cash and marketable securities, have urged it over the years to buy everything from Facebook FB and Yahoo YHOO to Sony SNE , Adobe and Disney DIS . Last quarter, Apple finally made a major acquisition. And what did it buy? It bought Apple. By my (revised) calculation, the company spent $16 billion last quarter ($4 billion in cash, $12 billion through the so-called accelerated share repurchase program) to purchase 32.5 million of its own shares at an average price of about $492. For that kind of money, Apple could buy Nokia NOK . Or BlackBerry BBRY three times over. “One way to think of it,” Asymco‘s Horace Dediu says in his Apple Q3 RY13 Review, “is this is Apple’s greatest acquisition ever.” Most of those shares — about 22 million — were retired in fiscal Q3, leaving Apple with 908 million shares outstanding, according to its latest 10-Q. The rest will be retired in Q4. UPDATE: Dediu has taken a crack at nailing down these somewhat fuzzy numbers. He gets an average per share price of $488.25. See Apple’s biggest acquisition. UPDATE 2: The spreadsheet above was revised to reflect the commentary below by readers who clearly understand better than I do the mechanics of share repurchase programs.