Googol is not the greatest number. There is googol 1, googol 2, googol 3, etc.. etc....
There is also infinity, which comes after 999 with a 100 zeros after it I'm guessing.
999,(100 9's)
999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999,999 999,999,999,999,999,999,999,999,999