I can recommend SpeedCrunch. Free and open source, comes in an installer free (USB/portable) version, and as for checking the value of the number in the topic, simply type hex(17281580835365214242). It supports Windows as well as OS X.
SpeedCrunch is great too, it was originally inspired by the WinXP PowerCalc - probably the best calculator from Microsoft: http://dan.hersam.com/2010/11/10/powercalc-in-windows-7/ (SpeedCrunch still lacks the graph rendering part, though has other features and improvements)
I adore SpeedCrunch. I don't have fancy large number requirements but I love the interface. It works on Linux too, though I think it's an old version in the Ubuntu repository so you might prefer to download the source instead.
Absolutely! love this calculator miles ahead of anything Windows has ever offered