C progran :To reverse the digits of N. Let us denote this number by R. You must output N+R.

#include<stdio.h>

int main()
{
  int num;
  int rev_num = 0, R=0,s=0;
  int N,t;
 
  scanf("%d",&num);
  N=num;
  t=num;
    while(t !=0)
    {
        rev_num = rev_num*10 + t%10;
        t = t/10;
    }
     R=rev_num;
    s=N+R;
   printf("%d",s);
}

Thanks
Happy Computing !