Is 309 A Prime Number
A prime number is a whole number with exactly two integral divisors, 1 and itself.
Let's check 309 number is prime.
Check 309 Prime Number Or Not
Factors of 309 :- 1
- 3
- 103
- 309
The factors number for 309 is 4 so it is greater than 2 , that's why it can not be prime number.
What Is Prime Number ?
Prime numbers are positive integers which have no divisors other than 1 and themselves so prime numbers can't be divided by other numbers than itself or 1. For example 2, 3, 5, 7, 11, 13, 17, 19, 23.... are the prime numbers.
How to check if a number is prime ?
The method we use is to try to divide it by all numbers from 1 to itself.
For example:
Let's check 42 prime or not ?
For number 42 we have to divide from 1 to 42 to find the remainder is equal to 0.
Divisors are : 1 , 2 , 3 , 6 , 7 , 14 and 21. So there more than 2 divisors.
The Answer : 42 is not a prime number.
Another example:
Let's check 17 prime or not ?
For number 17 we have to divide from 1 to 17 to find the remainder is equal to 0.
1 and 17 are the only divisors for 17. There are 2 divisors.
The Answer : 17 is a prime number.