Two is the next positive integer after one. Discovered in prehistory, 2 is the smallest prime natural number.
Two is an even number. It is the only even prime number, which makes it decidedly odd.
This is a bit of a cheat really as even means divisible by two - it is equally true to say: "Uniquely seventeen is both divisible by seventeen and prime."
Two is however one of only two numbers in that squaring it is the same as adding it to itself (2 + 2 = 22 = 4) (the other one is 0). And, "squaring" zero would be better calling "rounding", making 2 even more unique.
Two is also the dirtiest number, since you go it. To avoid the filthiest language, we call this a "deuce".
Two can be as sad as one, it's the loneliest number since the number one.
Two out of three ain't bad.
Two is what you have tea for.
The number two in the bible
The number two is very significant biblically. For example, two members of every unclean animal "kind" were allowed into the Ark whereas seven members of every clean animal "kind" were allowed to board. Oddly, in both cases, they would share one room.