Question: why 1 is called composite number?
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. Natural numbers that have more than two positive factors are called composite . 1 has only one positive factor i.e. no. ... Hence 1 is neither prime nor composite.