# Program to find all Factors of a Number using recursion

Given a number N, the task is to print all the factors of N using recursion.

Examples:

Input: N = 16
Output: 1 2 4 8 16
Explanation:
1, 2, 4, 8, 16 are the factors of 16. A factor is a number which divides the number completely.

Input: N = 8
Output: 1 2 4 8

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: The idea is to create a function that takes 2 arguments. The function is recursively called from 1 to N and in every call, if the number is a factor of N, then it is printed. The recursion will stop when the number exceeds N.

Below is the implementation of the above approach:

## C++

 `// C++ program to find all the factors ` `// of a number using recursion ` ` `  `#include ` `using` `namespace` `std; ` ` `  `// Recursive function to ` `// print factors of a number ` `void` `factors(``int` `n, ``int` `i) ` `{ ` `    ``// Checking if the number is less than N ` `    ``if` `(i <= n) { ` `        ``if` `(n % i == 0) { ` `            ``cout << i << ``" "``; ` `        ``} ` ` `  `        ``// Calling the function recursively ` `        ``// for the next number ` `        ``factors(n, i + 1); ` `    ``} ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `N = 16; ` `    ``factors(N, 1); ` `} `

## Java

 `// Java program to find all the factors ` `// of a number using recursion ` ` `  `class` `GFG { ` ` `  `    ``// Recursive function to ` `    ``// print factors of a number ` `    ``static` `void` `factors(``int` `n, ``int` `i) ` `    ``{ ` ` `  `        ``// Checking if the number is less than N ` `        ``if` `(i <= n) { ` `            ``if` `(n % i == ``0``) { ` `                ``System.out.print(i + ``" "``); ` `            ``} ` ` `  `            ``// Calling the function recursively ` `            ``// for the next number ` `            ``factors(n, i + ``1``); ` `        ``} ` `    ``} ` `    ``// Driver code ` `    ``public` `static` `void` `main(String args[]) ` `    ``{ ` `        ``int` `N = ``16``; ` `        ``factors(N, ``1``); ` `    ``} ` `} `

## Python3

 `# Python3 program to find all the factors ` `# of a number using recursion ` ` `  `# Recursive function to ` `# prfactors of a number ` `def` `factors(n, i): ` ` `  `    ``# Checking if the number is less than N ` `    ``if` `(i <``=` `n): ` `        ``if` `(n ``%` `i ``=``=` `0``): ` `            ``print``(i, end ``=` `" "``); ` `         `  `        ``# Calling the function recursively ` `        ``# for the next number ` `        ``factors(n, i ``+` `1``); ` `     `  `# Driver code ` `if` `__name__ ``=``=` `'__main__'``: ` `    ``N ``=` `16``; ` `    ``factors(N, ``1``); ` ` `  `# This code is contributed by Rajput-Ji `

## C#

 `// C# program to find all the factors ` `// of a number using recursion ` ` `  `using` `System; ` ` `  `class` `GFG { ` ` `  `    ``// Recursive function to ` `    ``// print factors of a number ` `    ``static` `void` `factors(``int` `n, ``int` `i) ` `    ``{ ` ` `  `        ``// Checking if the number is less than N ` `        ``if` `(i <= n) { ` `            ``if` `(n % i == 0) { ` `                ``Console.WriteLine(i + ``" "``); ` `            ``} ` ` `  `            ``// Calling the function recursively ` `            ``// for the next number ` `            ``factors(n, i + 1); ` `        ``} ` `    ``} ` ` `  `    ``// Driver code ` `    ``public` `static` `void` `Main() ` `    ``{ ` `        ``int` `n = 16; ` `        ``factors(n, 1); ` `    ``} ` `} `

Output:

```1 2 4 8 16
```

Time Complexity: O(N)

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.

Improved By : Rajput-Ji