The New York Times:

In its statement, Apple said it paid “an enormous amount of taxes” to local, state and federal governments. “In fiscal 2012 we paid $6 billion in federal corporate income taxes, which is 1 out of every 40 dollars in corporate income taxes collected by the U.S. government,” it said. In the 1980s, Apple was a pioneer of an accounting technique known as the “Double Irish With a Dutch Sandwich” [Don't try looking it up on Urban Dictionary], which reduces taxes by routing profits through Irish subsidiaries and the Netherlands and then to the Caribbean. Today, that tactic is used by hundreds of other corporations — some of which directly imitated Apple’s methods, say accountants at those companies. More recently, Apple has moved revenue to states like Nevada and overseas nations where the company pays less, or in some cases no, taxes.

One thing there isn’t a shortage of is different ways to make Apple’s current size look monstrous. Keep in mind this is just the United States, and Apple is now much bigger internationally.