Check prime numbers from a number to zero

#include <stdio.h>
#include <stdlib.h>

int main() {
    int num,i,j,c;

    printf("please enter the number?\n");
    scanf("%d",&num);

    for (j=1;j<=num;j++){ // count from 1 to NUMBER
        for (i=1,c=0;i<=j;i++){ //check for prime number and initialize c to zero
            if (j%i==0){
                c++;
            }
        }
        if (c==2){
             printf("%d\n",j);
        }
    }

    return 0;
}