# Find the first natural number whose factorial is divisible by x in C++

C++Server Side ProgrammingProgramming

We have to find the first natural number whose factorial is divisible by x. The x is given by the user. So if the x = 16, then output will be 6. as 6! mod 16 = 0. We will use general approach to solve this problem. iteratively count 1!, 2!, …. n! and check divisibility using x. If modulus is 0, then stop and return the number.

## Example

Live Demo

#include<iostream>
using namespace std;
int getNumber(int x) {
int fact = 1;
int i = 0;
while(fact % x != 0){
i++;
fact = fact * i;
}
return i;
}
int main() {
int x = 16;
cout << "Minimum value of N is: " << getNumber(x);
}

## Output

Minimum value of N is: 6
Published on 18-Dec-2019 11:26:52