Is 1 a prime number?

A prime number is a positive whole number that is only divisible by 1 and itself. The number 1 is divisible by 1, and it’s divisible by itself. Therefore it is not prime!

A positive number that is divisible by itself and 1 is called a prime number.

1 is divisible by itself and 1 and this is where it can get confusing.

I prefer to tell my students 'A prime number is positive number that is divisible by itself and 1 meaning it MUST have only TWO factors'. When you say this fact it is clear 1 is NOT a prime number as it only has 1 factor, i.e 1.