# 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 2

• 2 is the smallest prime number
• 2 is the only even prime number
• 2 is the only number whose factorial is prime
• For any polyhedron, 2 is the number of vertices plus the number of faces minus the number of edges
• The smallest field has 2 elements
• 2 is the only number that it is its own primorial, as well as its own factorial
• 2 is the only number that isn't n-polygonal with any n (submitted by Alexey Radul)
• 2 is the largest deficient factorial (submitted by Alexey Radul)
• 2 is the only prime which does not contain the letter E once spelled out (submitted by Aaron Diveley)
• 2 is the only difference between two consecutive primes which is prime
• 2 is the only number such that if you add it to itself or multiply by itself you would get the same number
• 2 is the only prime such that the sum of its divisors is another prime
• 2 is the only prime that lack letter e in its English name