A coprime is the common divisor of two integers only 1, which is called a coprime integer. Two natural numbers whose common divisor is only 1 are called coprime natural numbers, and the latter is a special case of the former.

1 is a multiple of any number, but it is coprime with any number. Because the factor of 1 is only 1, and the principle of prime numbers is: as long as the common factor of two numbers is only 1, two numbers are said to be prime numbers. Because 1 has only one factor, 1 is neither a prime number (prime number) nor a composite number, so it is impossible to find other common factors of 1 and other numbers. 1 and-1 are coprime with all integers, and they are the only integers that are coprime with 0.

How to write a prime number: If c and m are prime, write (c, m)= 1.

The definition of prime number in primary school mathematics textbooks is as follows: "The common divisor has only two numbers 1, which is called prime number."

The "binary number" mentioned here refers to the natural number.

"The common divisor is only 1", which cannot be mistaken as "no common divisor."

There is a misunderstanding that 0 and any number are not coprime. Strictly according to the definition of coprime, 0 and 1,-1 are both coprime. By expressing any rational number a/b(a, b is coprime, and b is a positive integer), we can also get that 0 and 1,-1 are certain coprime, otherwise 0 is not a rational number.