Add Digits of a Number

#include <stdio.h>

int main()
 {
 int n, sum = 0, remainder;

 printf("Enter an integer\n");
 scanf("%d", &n);

 while (n != 0) 
 {
  remainder = n % 10;
  sum = sum + remainder;
  n = n / 10;
 }

 printf("Sum of digits of entered number = %d\n", sum);

 return 0;
}

OUTPUT

Enter an integer
1659
Sum of digits of entered number = 21