Why is 17 a prime number?

Answer 1

17 is a Prime number because its only factors are 1 and itself.

The definition of a prime number is a natural number with no natural factors aside from 1 and itself. 17's only factors are 1 and 17 (itself), and therefore is a prime number.

Answer 2

YES. 17 is a prime number because the factors of 17 are only 1 and itself.

The numbers which has other factors aside from 1 and themselves are called composite numbers. Example: 9, 12, 15 & 18.