Program to find sum of digits of a number

#include<iostream.h>
#include<conio.h>
void main()
{
clrscr();
unsigned long i,t,n,sum=0;
cout<<"\n Enter a number : ";
cin>>n;
while(n!=0)
{
t=n%10;
sum+=t;
n=n/10;
}
cout<<"\n\t Sum of digits is : "<<sum;
getch();
}


                                                        Output