They only have two factors each.
13 prime 63 composite 61 prime 31 prime Well the question should have been either, Which one of these numbers is not a composite number? Or, Which one of these numbers is not a prime number?
prime numbers above 13 = 17, 19, 23, 29, 31,...
No prime number can equal 13, 5, 31, 7, 53 and etc.
31 is a prime number
403 is composite. It can be evenly divided by 13: 403/13 = 31.
1 and 31 (31 is a Prime number).
The only prime number among the options given is 31. A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. In this case, 31 cannot be divided evenly by any other number except for 1 and 31, making it a prime number.
31 is a prime number
31 is prime so 31 is the prime factorization of 31
Another pair of emirps between 10 and 100 is 13 and 31. An emirp is a prime number that results in a different prime number when its digits are reversed. Both 13 and 31 are prime, making them a valid pair of emirps.
31 is already a prime number.
39 is not prime because 13 and 3 are factors of it. To be prime the number cannot have any factors except itself and 1.