Common divisor, also called "common factor" If an integer is a divisor of several integers, it is called their "common divisor"; The greatest common divisor is called the greatest common divisor

Prime number:

Prime numbers are also called prime numbers. Refers to a natural number greater than 1, except 1 and the integer itself, which cannot be divisible by other natural numbers. In other words, a natural number with only two positive factors (1 and itself) is a prime number. Numbers greater than 1 but not prime numbers are called composite numbers. 1 and 0 are neither prime numbers nor composite numbers.

Composite number:

Refers to a natural number that can be divisible by other numbers except 1 and this number. Numbers greater than 1 but not prime numbers are called composite numbers.

Prime number:

The definition of prime numbers in primary school mathematics textbooks is as follows: two natural numbers whose greatest common factor is 1 are called prime numbers.

The "two numbers" mentioned here refer to all natural numbers except 0.

"The common factor is just.

1 "cannot be mistaken for" no common factor ". "

Quality number:

Ah! Prime number is prime number, prime number is prime number, but what is "prime number"! Ha ha! No one really knows!