the number 6

Here is the Wikipedia article on this number.
Here are some matters relating to the number 6 that this Wikipedia article missed:
1. 6 is a binomial coefficient
2. de Mere’s problem involves rolling a 6
3. the smallest number of people such that there is always either a group of 3 mutual strangers or a groups of 3 mutual acquaintances is 6
4. the peaks in the frequency distribution of the prime gaps occur at multiples of 6
keywords:
[Mathematics]
[list of properties]
[errors and omissions]
[Number Theory]
[significance]