When a typical calculator is asked to find 555^555, it causes an overflow error, and returns an error message. Not Google’s calculator, though.
Infinity? 555^555 is absurdly large, but it isn’t infinite. Just for starters, 555^555 + 1 is bigger. Infinity is larger than any number. It’s as far from 555^555 as it is away from the number one — an infinite distance, on any number line. Hopefully, as Google continues getting smarter, this will get fixed.