Why is 1 Not a Prime Number?

Answer: 1 is not a prime number because it only has one factor, which is itself. A prime number has exactly two factors.

Let’s break it down:

1. Prime Numbers Definition:
   • Prime numbers are natural numbers greater than 1. They have exactly two distinct positive divisors: 1 and the number itself. For example, 2, 3, 5, 7, 11, etc., are prime numbers.
2. Divisors of 1:
   • The divisors of 1 are 1 itself. In other words, 1 has only one positive divisor, which is 1.

Hence, for a number to be a prime number it must have 2 divisors i.e. 1 and the number itself and because the number 1 has only one divisor, it is not a prime number.