A divisor of n that is not 1 , 1 , n or n is known as a non-trivial divisor ; numbers with non-trivial divisors are known as composite numbers , while prime numbers have no non-trivial divisors . 1 , 1 , n and n are known as the trivial divisors of n. A divisor of n that is not a trivial divisor is known as a non-trivial divisor . A number with at least one non-trivial divisor is known as a composite number , while the units -1 and 1 and prime numbers have no non-trivial divisors .