What numbers are neither prime nor composite?

Question:

What numbers are neither prime nor composite?

Answer and Explanation:

A prime number is a positive integer that has only 1 and the number itself as its factors. In other words, a prime number is a positive integer that is only divisible by 1 and itself. For example, 29 is a prime number: it has only 1 and 29 as its factors, which means that 29 is only divisible by 1 and 29.

All other positive integers are called composite numbers. By definition, a composite number is a positive integer that has factors other than 1 and itself. In other words, a composite number is a positive integer that is divisible by 1, itself and other numbers. For example, 28 is a composite number: 28 has 1, 2, 4, 7, 14, and 28 as its factors, which also means that 28 is divisible by 1, 2, 4, 7, 14, and 28.

Given these definitions, only the number 1 is neither prime nor composite.

Learn more about this topic:

Identifying Prime & Composite Numbers

from 6th-8th Grade Math: Practice & Review

Chapter 4 / Lesson 3
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