For 9 to be a prime number it would have been required that 9 has only two divisors ie itself and 1. A Prime number has exactly two factors so 1 cannot be prime because it has only one factor - itself. Prime And Composite Numbers Math School Studying Math Learning Math The definition of even number is. . First few prime numbers are. Always remember that 1 is neither prime nor composite. Yes 2 is a prime number. So 2 is a Prime Number or Not. Now the factors of 2 are 1 and 2. 1 3 5 15. For 15 the answer is. And we stop as soon as we find a factor. Is 9 a prime number. 1 2 3 6 9 18. Stuff have definitions. Some interesting fact about Prime numbers. For example if N is 49 the smallest factor is 7. It is possible to find out using mathematical methods whether a given integer is a prime number or not. For that reason 1 couldnt have. An even number is an integer