C Program to Reverse a given number using Recursion

/*C Program to Reverse a given number using Recursion:*/

#include<stdio.h>
int main(){
   int number,reverse_number;

   //User would input the number
   printf("Enter a Number to Reverse: ");
   scanf("%d",&number);

   //Calling user defined function to perform reverse
   reverse_number=reverse_function(number);
   printf("Reversed Number is %d",reverse_number);
   return 0;
}
int sum=0,remainder;
int reverse_function(int num){
   if(num){
      remainder=num%10;
      sum=sum*10+remainder;
      reverse_function(num/10);
   }
   else{
      return sum;
	   }
   return sum;
}

Enter a Number to Reverse: 865
Reversed Number is 568
--------------------------------
Process exited after 4.46 seconds with return value 0
Press any key to continue . . .