28 and 32
8 and 16, among others.
Composite numbers have more than two factors. So, the numbers which have two or less than two factors are not composite numbers. Numbers which have exactly two factors are prime numbers. 1 is an exceptional case because it is neither prime nor composite since it has only one factor which is 1.
Prime numbers have two factors, composite numbers have more than two.
Composite numbers have more than two factors.
Two is prime. All other even numbers are composite.
25 and 36
8 and 16
Composite numbers have more than two factors. Once you find a third factor, you know your number is composite.
If the GCF of two composite numbers is 1, they are co-prime or relatively prime.