What does prime number mean?

A prime number is a nonzero natural number, and its common factor is only 1. Two nonzero natural numbers whose common factor is only 1 are called coprime numbers.

Prime numbers have the following theorems:

(1) Two nonzero natural numbers whose common factor is only 1 are called prime numbers; For example: 2 and 3, the common factor is only 1, which is a prime number;

(2) A positive integer whose greatest common factor is only 1 is called a prime number;

(3) Two different prime numbers are coprime numbers;

(4) 1 is coprime with any natural number. Two different prime numbers are coprime. A prime number and a composite number are coprime when they are not multiples. The coprime of two complex numbers without the same prime factor;

(5) Any two adjacent numbers are coprime;

(6) The probability that two positive integers are prime numbers (the greatest common divisor is 1) is 6/π 2.

Extended data:

Because one and any nonzero natural number are coprime, the product obtained by multiplying one and any nonzero natural number is not necessarily a composite number. For example, 1 and 17 are coprime, and 1× 17= 17 is not a composite number.

The common divisor of two numbers is only 1, which is called prime number. According to the concept of coprime number, we can judge whether a group of numbers are coprime. For example, if the common divisor of 9 and 1 1 is only 1, then they are prime numbers.