Question

why 1 is not a prime no?

Answer 1

Definition ofprime! An integer greater than one is called a prime number if its only positive divisors (factors) are one and itself.

Answer 2

A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. ... For example, 5 is prime because 1 and 5 are its only positive integer factors, whereas 6 is composite because it has the divisors 2 and 3 in addition to 1 and 6.