C Program to Find Factorial of a Number Using Recursion

The factorial of a positive number n is given by :

factorial of n (n!) = 1 * 2 * 3 * 4 *...  * nâ€‹

The factorial of a negative number doesn't exist. And the factorial of 0 is 1.

Program :

#include<stdio.h>
long int multiplyNumbers(int n);
int main() {
    int n;
    printf("Enter a positive integer: ");
    scanf("%d",&n);
    printf("Factorial of %d = %ld", n, multiplyNumbers(n));
    return 0;
}

long int multiplyNumbers(int n) {
    if (n>=1)
        return n*multiplyNumbers(n-1);
    else
        return 1;
}

Output :

Enter a positive integer: 56
Factorial of 56 = 6908521828386340864