Is 1 a prime number

Is 1 a prime number

Is 1 a prime number?

Definition of prime number: A divisor has only 1 and its own number. Under this definition, it is not explicitly stated that 1 is not equal to itself, that is, the divisor is not emphasized to be 2, so this definition does not exclude 1 as a prime number.

Later, it was clearly defined: A positive integer with a (positive) approximation of 2 is a prime number. In this case, 1 is not considered a prime number because it has only one divisor.

This definition also depends on the prime factorization of the number.

Decomposing a number into the product of prime numbers, sorted from smallest to largest, and expressing the cumulative multiplication of the same prime factor as a power form, is called standard prime factor factorization.

In this case, 1 is excluded from the prime number, and then the standard prime factor factorization has a unique representation. This is the fundamental theorem of arithmetic.

Other than that:

1. Prime numbers are also called prime numbers, and prime (number) factors (divisors) are similar.

Second, the concept of natural numbers has also changed historically. Prior to 1993, the mathematical community in our country equated the set of natural numbers with the set of positive integers; In other words, after 1993, 0 was classified as a natural number.