Number One

What Makes Integer Number One Unique?

The integer number One, sometimes referred to as unity.

One is the integer before Two and after Zero.
One is the first non-zero number in Natural Numbers as well as the first odd number in Natural Numbers.
Any number multiplied by one is that number, as one is the identity property for multiplication - Properties Of Multiplication.
It is also important to note that one is neither a Prime Number nor a Composite Number.