There are many different problems that can involve prime numbers: some can be solved very easily, others (prime factorisation designed for secure data transmission) are designed to be virtually impossible to solve. So the question needs to be more specific.
What problem?
it is a prime number
a square number is a multiplicatin problem that is the same for an example 6x6=36 because it makes a square a prime number is basicly a problem that has no multiplicatin problem except a 1 for an exsample 11x1=11
A prime number can not be divided, without a remainder, by any other number except itself and 1.
Well, look. This number is huge but that si not a problem. Notice how it ends in 4? well that means it can be divided by 2! so it is not a prime number.
It is: 1*17 = 17 which is a prime number
It is: 1*79 = 79 which is a prime number
This number is prime, and prime means that there are no numbers that equal this problem. Except for:1 and itself (40)
2 x 2 x 3 x a
The ones with prime number roots.
It is: 1 times 233 = 233 which is a prime number
There are fewer prime numbers than odd numbers. Adjust your preference accordingly.