The number 2 is a prime number. It is the smallest prime number and the only even number that is prime. Its only two factors are 1 and 2.
The number 1 is not a prime number. A prime number by definition is a positive integer greater than 1 that is evenly divisible by only itself and 1.
Nine is not a prime number. It is a composite number, because it has more than two factors. A prime number is only divisible by one and by itself, and nine is divisible by one and by nine, but it is also divisible by the number three.
Two is a prime number. Two is the smallest prime number and the only even prime number, since all other even numbers divide by two.
The prime factors of 6 are 2 and 3. The number 6 cannot be factorized into any other combination of prime numbers. A prime number is a whole number larger than 1 which can only be divided by 1 and itself.
The number zero is not a prime number. By definition, a prime number dictates that the number must be a whole number greater in value than one and must be divisible by only itself and one.
The number 3 is a prime number. A prime number is a positive number that can only be divided evenly by the number 1 and itself.