1. Only 1 and its own natural number are called prime numbers. In other words, a prime number has only 1 and its own two divisors.

2. A prime number is an integer, which can be expressed as the product of itself and 1, but it cannot be expressed as arbitrary.

The product of any other two integers. For example, 15 = 3× 5, then 15 is not a prime number;

Another example is 12.

= 6× 2 = 4× 3, so 12 is not a prime number. On the other hand, 13 is equal to13x1.

Outside, it cannot be expressed as the product of any other two integers, so 13 is a prime number.

After answering, I hope it will help your question. If you are satisfied, please use o(∩_∩)o ... haha.