A googolplex is the number 10^googol, which means it's a 1 followed by a googol of zeros (i.e. 10100 zeros).
1 googolplex
= 10^googol
= 10^10^100
= 1010,000,000,000,000,000,000,000,000,000...
As for the largest number, that'd be Graham's number.
I did my best for not knowing how to writee english. I used translate so sorry if this doesn't make much cense! (:
