# Number Gossip

(Enter a number and I'll tell you everything you wanted to know about it but were afraid to ask.)

## Unique Properties of 21

- 21 is the smallest number of distinct integer-sided squares needed to tile a square
- 21 is the number of spots on a standard cubical die (1+2+3+4+5+6)
- 21 is the number of connected graphs with 5 vertices
- 21 is the first century with ten prime years