# 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 1105

- 1105 is the smallest Carmichael number whose reversal is prime
- 1105 is the smallest pseudoprime to both base 2 and base 3. BTW, it is also a pseudoprime to base 7
- 1105 is the largest 4-digit pseudoprime to base 2
- 1105 is the smallest hypotenuse of exactly 13 distinct Pythagorean triangles
- 1105 is the smallest number such that n, n+1 and their sum have at least 3 distinct prime factors
- 1105 is the smallest hypotenuse of a right triangle which is the product of three distinct odd primes
- 1105 is the smallest Carmichael number that is the sum of two squares
- 1105 is the smallest Fermat pseudoprime to base 2 that is decagonal