What do you call a number that is not prime?

Could you please elaborate on what you mean by "a number that is not prime"? Are you referring to a specific mathematical term or concept that describes numbers that do not meet the criteria of being prime? If so, the most direct answer would be that a number that is not prime is simply called a "composite number". Composite numbers are those that have more than two distinct positive divisors, meaning they can be factored into other numbers besides 1 and themselves. For example, 4, 6, 8, and 9 are all composite numbers because they can be divided evenly by other numbers besides 1 and themselves. Is there a specific aspect of composite numbers or non-prime numbers that you'd like me to further explain or clarify?