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 409
- 409 is the smallest prime which along with both its neighbors uses non-prime digits (401, 409, 419)
- 409 is the smallest prime number such that every digit of it and its index contains a loop (only digits 0, 4, 6, 8, 9 are allowed)
- 409 is the smallest prime that yields a square after deleting its zeros