C program to find factorial using function  and recursion :  

 In this program, we will read a number and then find (calculate) of factorial of that number using recursion.

What is factorial: Factorial of a number is the product of that number with their all below integers.
For example (Factorial of 5) is: !5 = 5*4*3*2*1 = 120

!5  thats means    5* !5-1 

or !5 = 5*!4

Example : 

   Input   : Enter the number 5 

  Output : factorial = 120 

Code : 

#include<stdio.h>

 long int  fact(int number)

{

    if(number==0)

    return 1;

    return number*fact(number-1);

}

int main()

{

     int n;

    printf("Enter the factoril number : ");

    scanf("%d",&n);

      long int  bb=fact(n);

    printf(" factorial =  %ld",bb);

    return 0;

}

output : factorial = 120