What is a prime number?

A prime number is defined as a number that has exactly two distinct positive divisors. These divisors are the number itself and 1. For example, the number 5 is prime because its only divisors are 1 and 5. This definition is foundational in number theory and is crucial for understanding concepts related to factors and multiples.

The other provided definitions do not accurately capture the characteristics of prime numbers. While it is true that a prime number is divisible by 1 and itself, simply being divisible by these two does not fully reflect the requirement that it has no other positive divisors. The definition excludes numbers less than 2, as prime numbers must be greater than 1, and it specifically applies to whole numbers, so any reference to non-whole numbers misses the mark entirely. The notion that a prime can be factored into two or more whole numbers contradicts the very essence of what makes a number prime, as prime numbers cannot be factored into smaller natural number components aside from 1 and themselves.