The number of possible permutations for card order in a standard deck of playing cards, 52! (52 factorial, or 52x51x50x49 . . . all the way down to x1), is staggeringly large. How large?
Yannay Khaikin, who created this lovely video explaining the concept, says it’s this large:
Any time you pick up a well shuffled deck, you are almost certainly holding an arrangement of cards that has never before existed and might not exist again.
Seeing this mathematical concept explained through cards is one of the coolest things I’ve encountered all week.