What is the primary characteristic of a prime number?

A prime number is defined as a natural number greater than 1 that has no positive divisors other than 1 and itself. This means that a prime number can only be divided evenly (without a remainder) by the number 1 and the number itself. For example, the number 7 is prime because its only divisors are 1 and 7.

In contrast, other choices do not accurately describe prime numbers. While a prime number must be greater than 1, it is not restricted to being even, as evident by the prime number 3. Although some prime numbers can be divided by 2, not all can, since 2 is the only even prime number. Additionally, stating that prime numbers are less than 10 is inaccurate, as there are many prime numbers greater than 10, such as 11, 13, and 17. Thus, the primary characteristic of a prime number is that it is divisible only by itself and 1.