The number 2

Even though 2 is such a small number, there are various properties illustrating the usefulness of this number.

First of all it is the second number in the natural number system.
It is an even number and also the only even number which is a prime number.
It helps us to determine whether an integer number is even, i.e. a number is even when it can be divided by 2.
The Roman numeral for 2 is II.
In some situations 2 can be called a couple or a pair, for instance two socks is called a pair of socks.
If we divide 100 by 2² we arrive at 25, the previous two number which I have discussed (see: The number 25, The number 100).
Being number 2, you can also say being second. In a medal race this would usually mean that you will receive the silver medal.
Number 2 is a fictional character in the Austin Power movies.
In terms of imaginary number we can write 2 as the product: 2 = (1+i)(1-i).
When we draw graphs we usually draw it in a 2-dimensional space, the xy-plane.

If you know of any other interesting facts, which I'm sure there are many of, please leave a comment.