It is a prime.
31 is prime.
31 is a prime number
Composite. Its prime factors are 23 and 31.
961 is not prime. 961 = 31 * 31
39 is a composite number 1 is neither prime nor composite number 31 and 41 are prime numbers.
31 is prime.
31 is a prime number
31 is prime.
21 is composite number that is a multiple of 3. 31 is a prime number.
No, it is a prime number.
31 is a prime number.