Can an even number be a prime number?

Yes. The number 2 is even and is classed as a Prime number because it can only be divided by itself and 1 (the definition of a prime number). All other even numbers cannot be prime numbers as they can all be divided by 2.
There is only 1 even number that is prime. It is 2. Besides that, every other number can go into it. It's because prime numbers can only go into itself and 1. Other numbers are composite meaning that they have other factors besides itself and 1.