# Problem

Write a program in C to check whether a number is a prime number or not.

# How to find if a number is a prime number in C ?

A Prime Number is a number that is divisible by 1 and by itself. Some of the examples of the prime number are 2 , 3 , 5 etc.

Here’s a program in C demonstrating how to find whether the given number is a prime number or not.

#include <stdio.h> int main() { int input, index; int flag=0; printf("Abundantcode.com coding sample \n"); printf("Enter a number : "); scanf("%d",&input); for(index=2; index<=input/2; ++index) { if(input%index==0) { flag=1; break; } } if (flag==0) printf("%d is a prime number.",input); else printf("%d is not a prime number.",input); return 0; }

### Output

Abundantcode.com coding sample

Enter a number : 7

7 is a prime number.

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