Does number [1] a prime number ?

Published On :2020-12-22 00:50:00

The number 1 is not a prime number Why?

 First: What is the prime number: It is that which can be divided by 1 and by itself

 Example: {........, 2,3,5,7,11}

 So it looks like the number 1 should be a prime number, right?

 Because it applies the definition of a prime number?

 In the past, it was considered a prime number, but after the advance of science, mathematicians had to exclude it from the primes.

 Why?

 Eliminate for good reason, there's an important theory in mathematics called

 "The Fundamental Theorem of arithmetic"

 It says that any positive integer must be a prime number or it can be written as a unique and distinct form of multiplying primes.

 Not understood?  Bringing an example would be a good solution

 15 is a positive integer, not a prime

 So 15 = 3 * 5

 But there is an important word in the theory "distinct."

 But

 15 = 3 * 5

 15 = 3 * 5 * 1

 15 = 3 * 5 * 1 * 1

 Here is the problem!  If 1 were a prime number, we wouldn't have a unique way of writing it as a multiplication of primes.

 So they had to exclude 1 out of the theory

 It became a number of primes except for 1.

 This is a reason to exclude 1 from the prime numbers.

 So 1 is not a prime or complex number