Prime Number

Prime Number is a number which is only divisible by 1 and the number itself i.e., it has no factors other than 1 and itself.

Example 1: 7 is only divisible by 1 and itself only. Hence it is a Prime Number.

Example 2: 4 is divisible by 1 and 2 and 4. Hence it is not a Prime Number.

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