Two
2 is an even number.
2 is a prime number, which means it is only divisible by 1 and itself.
2 is a palindrome.
2 is a Sophie Germain prime, which means that 2 x 2 + 1 = 5 is also a prime number.
2 is a Harshad number, which means it is divisible by the sum of its digits (2 = 2, and 2 is divisible by 2).
In binary, 2 is represented as 10.
In hex, 2 is represented as 2.
2 is an Armstrong (or Narcissistic) number, which means it is the sum of its own digits each raised to the power of the number of digits.
2 is the factorial number of 2 (2! = 1 x 2 = 2).
2 is the 3rd Fibonacci number.
Prime factorization of 2: 2.