Apple have the problem 145 billion times over but as they are likely to be further up the que than say you or me are their Dollar Bills more real than yours. That divides the question further into do all depositors have equal claims in practice ( Cyprus shows that this is not necessarily so). Deposit Guarantee schemes again would suggest that for the first few tens of thousands every account is equal and those with larger amounts are not as protected( again Cyprus seems to suggest that the actual practice of international banking does not confirm this intuitive conclusion).
We can then get into the matter of degrees of reality can something be only a little bit real, or real for some and not for others?
For me Apple and its cash pile is not real at all either Physically or indeed metaphorically. Apple , the myths of consumerism and Apples so called success are all constructed according to metrics for which I personally have no respect or belief.
Chuck Prince famously said something about ”Dancing till the music stops´´ another great analogy to the precarious linkages that our financial system used to have to the reality it weasles into its public image. what he was basically saying is there are not enough chairs in the casino and your chips are only real if you manage to catch a seat at the table when the music stops. Its stopped again at the moment get the elbows out things are getting rough in the Wall street game of musical chairs again.