Is it a Prime Number?

primenum.c

#include <stdio.h>

int main(void) {
  int n,
    lcv,
    flag; /* flag starts as 1 and becomes 0 if it's determined that the
              number is not prime */

  printf("Enter value of the number\n");
  scanf("%d", &n);
  
  for (lcv=2, flag=1; lcv <= (n / 2); lcv++) {
    if ((n % lcv) == 0) {
      if (lcv == 2)
        printf("The factors of %d are:\n", n);
      printf("%d ", lcv);
      flag = 0;
    }
  }
  printf("\n");
  if (flag == 1)
    printf("%d is a prime number\n", n);
  else
    printf("%d is not a prime number\n", n);
}