Apple could buy every tech company not named Google (GOOG), Microsoft (MSFT), Facebook (FB), Amazon (AMZN) or Verizon (VZ).
But only Google and Microsoft are way out of Apple's reach -- it might be able to buy Amazon or Verizon in a quarter or two and Facebook in a year or so.
If Tim Cook got the buying itch, he could walk over to the headquarters of Oracle (ORCL), Intel (INTC), AT&T (T), IBM (IBM), Cisco (CSCO) or Qualcomm (QCOM) with enough cash to buy any of those companies.