#include <stdio.h>
 
int factorial(unsigned int);
 
 
 
int  main()
 
{
 
    int i = 8;
 
    printf("Factorial of the number %d is %d\n", i, factorial(i));
 
    return 0;
 
}
 
 
 
int factorial(unsigned int i)
 
{
 
   if(i < 2) 
 
   {
 
      return 1;
 
   }
 
   return i * factorial(i - 1);
 
}

Output:

Factorial of the number 8 is 40320