So tomorrow the world is supposed to end. Okay, not quite. The rapture will begin. Apparently Earth won’t be destroyed until October 21. So you have some time to get your [email protected]*% together.

But this isn’t the only reason that the number 21 is significant. Here are some other interesting (in a pocket-protector kind of way) facts about this Very Important Number.

- 21 is the sum of the dots on a die: 1 + 2 + 3 + 4 + 5 + 6 = 21
- 21 is a Fibonacci number: 1, 1, 2, 3, 5, 8, 13, 21, …
- 21 is the third “star number.”
- 21 is smallest number of differently sized squares that are needed to tile a square.
- 21 is the legal drinking age in the U.S. (Not so math geeky, eh?)
- Blackjack baby!
- [pmath]{2^21}-21[/pmath] is a prime number.

Anything you want to add? Or are you too busy packing your bags?