Apple buys a company every two to three weeks on average, CEO Tim Cook told CNBC.

In roughly the last six months alone, Cook said, Apple has bought approximately 20 to 25 companies. Apple often doesn't announce these deals because the companies are small and Apple is "primarily looking for talent and intellectual property," Cook told CNBC's Becky Quick in an interview from Berkshire Hathaway's annual shareholder meeting over the weekend.

The aggressive acquisition style highlights Apple's massive purchasing power. In its fiscal second-quarter earnings statement, Apple reported a $225.4 billion cash hoard, making it one of the most cash-rich companies in the world. Apple has pledged to contribute $350 billion to the U.S. over five years through expansion and taxes on repatriated cash.

Cook said that after investing in initiatives like its new $1 billion campus in Austin, Texas, the company turns its attention and spending to other goals.

"If we have money left over, we look to see what else we [can] do," Cook said. "We acquire everything that we need that can fit and has a strategic purpose to it. And so we acquire a company on average, every two to three weeks."

This strategy shines through in some of Apple's more high-profile acquisitions. Its 2018 acquisition of digital magazine subscription service Texture, for example, was a prelude to its new Apple News+ service that offers access to a variety of publications for a flat fee.

Even though Apple acquires several companies a year, it's famous for not making major acquisitions. Its largest in recent memory was its $3 billion purchase of Beats in 2014. Apple turned Beats into its Apple Music streaming service and continues to sell Beats headphones as part of its growing wearables category.

Apple has also reportedly mulled other major acquisitions, including Time Warner in 2016, according to a Wall Street Journal report at the time. Some have called on Apple to use its cash pile to make large acquisitions of companies like Tesla or Netlfix.

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