Palindrome_recursion.c

#include <stdio.h>
#include <math.h>
int num(int n);
int main()
{
	int i;
	scanf("%d",&i);
	if(num(i)==i)
	{
		printf("Palindrome\n");
	}
	else
	{
		printf("Not a palindrome\n");
	}
}
int num(int n)
	{
	//Finds total number of digits
    	int digit = (int)log10(n);
    
    	// Base condition
    	if(n == 0)
       	 return 0;
	
    	return ((n%10 * pow(10, digit)) + num(n/10));
	}

Don't use pointers to pass values unless necessary. Pass the copy of values. And don't use recursion unless necessary.