43,252,003,274,489,856,000 (Forty three quintillion ...)
The Rubik's Cube is advertized as having billions of possible
permutations, but that is only because it was thought that the general
public would be unable to comprehend the actual number:
43,252,003,274,489,856,000. If you had a Rubik's Cube for each of its
possible permutations and laid them side by side, they would stretch for
261 light years!