With 6 colored sides, 21 pieces and 54 outer
surfaces, there's a combined total of over 43 Quintilian different possible
configurations. To put that into perspective: if you turned the Rubik's cube
once every second it would take you 1400 trillion years to finish to go through
all the configurations. If you had started this project during the Big Bang, you
still wouldn't be done yet.

Another way to think about this is, if a
person had as many Rubik's cubes as there were possible configurations, they
could cover the surface of the Earth 275 times. And if one considers the number
of configurations you could reach by disassembling and reassembling the cube,
the number would be nearly 12 times that many.