Using divisibility rules, is 207 prime or composite?
207 is prime because it is not divisible by 2, since it does not end in an even number, and it is not divisible by 3 since it does not end in an odd number.
207 is not prime because it has more than one factor: it is divisible by 3, since 2+0+7 = 9, which is divisible by 3.
207 is prime because it is not divisible by 2 or by 5, since it does not end in an even and does not end in 5 or 0.