Biggest number in computer ever

Question

Just asked by my 5 year old kid: what is the biggest number in the computer?

We are not talking about max number for a specific data types, but the biggest number that a

Answer 1

I'll try to give a practical answer.

Common Lisp number crunching is particularly powerful. It has something called "bignums" which are integers that can be arbitrarily large, limited by the amount of available.

See: http://en.wikibooks.org/wiki/Common_Lisp/Advanced_topics/Numbers#Fixnums_and_Bignums

Answer 2

Bits are not numbers. You, as a programmer, give them the meaning you want, possibly numbers.

Now, I decide that 1 represents "the biggest number ever thought by a human plus one".