# 5

This number is a prime.

Just showing those entries submitted by 'Post': (Click here to show all)

5 is the first Centered Square Prime Number. [Post]

The first prime Apéry number. [Post]

5 is the smallest prime numerator of a Bernoulli number. [Post]

Adams was the first with a prime number of letters in his last name, among the Presidents of the United States of America. Obama is the most recent. [Post]

The only greater of twin primes, written in base 6, not to end with the digit 1. Because all but the first greater of twin primes is of the form 6n+1, hence ends with (base 6) the digit 1. [Post]

There are 5 topological symmetry types for oriented knots: fully symmetric, reversible, +amphicheiral, -amphicheiral, and asymmetric. Not to be confused with prime knots. [Post]

The concept of a regular polyhedron of index two was introduced in Wills for orientable polyhedra with planar faces. There are exactly 5 such polyhedra. [Post]

There are five countably infinite Ramsey classes of permutations. [Post]