Question: what do you call a number that is neither prime nor composite?
Answer: A natural number (i.e. 1, 2, 3, 4, 5, 6, etc.) is called a prime number (or a prime) if it has exactly two positive factors, 1 and the number itself. ... 1 has only one positive factor i.e. no. 1 only. Hence 1 is neither prime nor composite. It forms its own special category as a "unit".