First, except for the number 2, all prime numbers are odd, since an even number is divisible by 2, which makes it composite. So, the distance between any two prime numbers in a row (called successive prime numbers) is at least 2.

Are prime numbers ever even?

There is only one even prime number, that is, 2. Any two prime numbers are always co-prime to each other.

How many prime numbers are even?

It means all the other even numbers will have at least three factors, so they can not be a prime number. Hence, there is only one number '2' which is prime and even both. Hence, the answer of the given question is 1.