You can find here, Googol+, an amazingly powerful arbitrary precision calculator. You need to try it, even if just to be aware that this sort of things does indeed exist. Odds are that you have already dreamed for a toll like Googol+, we did but had to build it. Price: $29.95.

We have also Random Labs. Even though, at first it does not sound like that, the generation of good random numbers is an extremely difficult task. Random Labs allows you to obtain True Random numbers and  Cryptographically Secure Pseudo Random numbers. With them you can generate random passwords and evaluate how strong they are or you may opt for the more frivilous affair of generating random Lotto numbers. Try also this one, it is worthwhile. Price: Free.

Finally, we have Went, a software for testing the quality of random numbers. Went is based on the Public Domain Ent software, but revamped for Windows. Price: Free.