Any number and its inverse example 4 x 1/4=1 2x 1/2=1
An even number
You need two numbers to have a product.
They are the products of two distinct prime numbers. Along with one and the numbers themselves, they all total four factors.
When one of the numbers is a factor of the other.
Products of prime numbers are composite numbers.
Two factors are multiplied to make a product.
They are the composite numbers, products of primes and their multiples. All even numbers are composite, except the number two (2) which is prime.
When one of the numbers is a factor of the other.
One of the numbers is a factor of the other.
The GCF of two numbers is one of the two numbers when one of the numbers is a factor of the other because a number can't have a factor higher than itself.
The products of non-prime numbers have more than two factors.
At least one of the two numbers has to be even, but both can be even.