Only one prime number is even. Which number is it? How do you know it is a prime number?
First think about the definition of even numbers. They are divisible by 2.Next think about the definition of prime numbers. They can only be divided by 1 and themselves.2 is the only number that matches both definitions. All other even numbers can be divided by 2, and therefore fail the requirement for the prime number definition.
2 because prime number divide 1 and itself and 2 also divide 1 and itself