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# C program to check whether a number is prime or not

## C program for how to check the given number is prime or not

Posted on 28 Sep 2017 Category: C Views: 177

Edited on 24 Jan 2018

## C program to check whether a number is prime or not

A prime number is a natural number that has only one and itself as factors. For example 2,3,5,7,11,… are some of the prime numbers. Here we will see the c program to check whether a number is prime or not. Below is the C code for the same.

``````#include <stdio.h>
#include <conio.h>
void main()
{
int n, i, count = 0;
printf("Enter any number n:");
scanf("%d", &n);
for (i = 1; i <= n; i++)
{
if (n % i == 0)
{
count++;
}
}
if (count == 2)
{
printf("%d is Prime ",n);
}
else
{
printf("%d is not a Prime number",n);
}
getch();
}
``````

Suppose the given number is 7, then in the 'for loop' it executes until the i value becomes 7.

In the first iteration i=1, then it checks whether n%i==0, if it is true count variable increments. This process repeats until i=7. When i=7 for loop terminates and come out of the loop and execute the next if statement. while executing the statement (count==2), then the given number is prime.

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