# Minimum divisor of a number to make the number perfect cube

Given a positive integer N, the task is to find the minimum divisor by which it shall be divided to make it a perfect cube. If N is already a perfect cube, then print 1.
Examples:

```Input : N = 128
Output : 2
By Dividing N by 2, we get 64 which is a perfect cube.

Input : n = 6
Output : 6
By Dividing N by 6, we get 1 which is a perfect cube.

Input : n = 64
Output : 1```

Any number is a perfect cube if all prime factors of it appear in multiples of 3, as you can see in the below figure.

Therefore, the idea is to find the prime factorization of N and find power of each prime factor. Now, find and multiply all the prime factors whose power is not divisible by 3 as primeFactor*power%3. The resultant of the multiplication is the answer.
Below is the implementation of the above approach:

## C++

 `// C++ program to find minimum number which divide n``// to make it a perfect cube``#include ``using` `namespace` `std;` `// Returns the minimum divisor``int` `findMinNumber(``int` `n)``{``    ``int` `count = 0, ans = 1;` `    ``// Since 2 is only even prime, compute its``    ``// power separately.``    ``while` `(n % 2 == 0) {``        ``count++;``        ``n /= 2;``    ``}` `    ``// If count is not divisible by 3, ``    ``// it must be removed by dividing``    ``// n by prime number power.``    ``if` `(count % 3 != 0)``        ``ans *= ``pow``(2, (count % 3));` `    ``for` `(``int` `i = 3; i <= ``sqrt``(n); i += 2) {``        ``count = 0;``        ``while` `(n % i == 0) {``            ``count++;``            ``n /= i;``        ``}` `        ``// If count is not divisible by 3, ``        ``// it must be removed by dividing``        ``// n by prime number power.``        ``if` `(count % 3 != 0)``            ``ans *= ``pow``(i, (count % 3));``    ``}` `    ``// if n is a prime number``    ``if` `(n > 2)``        ``ans *= n;` `    ``return` `ans;``}` `// Driven Program``int` `main()``{``    ``int` `n = 128;``    ``cout << findMinNumber(n) << endl;``    ``return` `0;``}`

## Java

 `// Java program to find minimum number which divide n``// to make it a perfect cube``import` `java.io.*;``public` `class` `GFG{`` ` `// Returns the minimum divisor``static` `int` `findMinNumber(``int` `n)``{``    ``int` `count = ``0``, ans = ``1``;`` ` `    ``// Since 2 is only even prime, compute its``    ``// power separately.``    ``while` `(n % ``2` `== ``0``) {``        ``count++;``        ``n /= ``2``;``    ``}`` ` `    ``// If count is not divisible by 3, ``    ``// it must be removed by dividing``    ``// n by prime number power.``    ``if` `(count % ``3` `!= ``0``)``        ``ans *= Math.pow(``2``, (count % ``3``));`` ` `    ``for` `(``int` `i = ``3``; i <= Math.sqrt(n); i += ``2``) {``        ``count = ``0``;``        ``while` `(n % i == ``0``) {``            ``count++;``            ``n /= i;``        ``}`` ` `        ``// If count is not divisible by 3, ``        ``// it must be removed by dividing``        ``// n by prime number power.``        ``if` `(count % ``3` `!= ``0``)``            ``ans *= Math.pow(i, (count % ``3``));``    ``}`` ` `    ``// if n is a prime number``    ``if` `(n > ``2``)``        ``ans *= n;`` ` `    ``return` `ans;``}`` ` `// Driver code``public` `static` `void` `main(String[] args)``{``    ``int` `n = ``128``;``    ``System.out.print(findMinNumber(n) +``"\n"``);``}``}` `// This code is contributed by Rajput-Ji`

## Python3

 `# Python3 program to find minimum number which divide n``# to make it a perfect cube` `# Returns the minimum divisor``def` `findMinNumber(n):``    ``count ``=` `0``;``    ``ans ``=` `1``;` `    ``# Since 2 is only even prime, compute its``    ``# power separately.``    ``while` `(n ``%` `2` `=``=` `0``):``        ``count``+``=``1``;``        ``n ``/``=` `2``;``    ` `    ``# If count is not divisible by 3,``    ``# it must be removed by dividing``    ``# n by prime number power.``    ``if` `(count ``%` `3` `!``=` `0``):``        ``ans ``*``=` `pow``(``2``, (count ``%` `3``));` `    ``for` `i ``in` `range``(``3``, ``int``(``pow``(n, ``1``/``2``)), ``2``):``        ``count ``=` `0``;``        ``while` `(n ``%` `i ``=``=` `0``):``            ``count ``+``=` `1``;``            ``n ``/``=` `i;``        ` `        ``# If count is not divisible by 3,``        ``# it must be removed by dividing``        ``# n by prime number power.``        ``if` `(count ``%` `3` `!``=` `0``):``            ``ans ``*``=` `pow``(i, (count ``%` `3``));``    ` `    ``# if n is a prime number``    ``if` `(n > ``2``):``        ``ans ``*``=` `n;` `    ``return` `ans;` `# Driver code``if` `__name__ ``=``=` `'__main__'``:``    ``n ``=` `128``;``    ``print``(findMinNumber(n));` `# This code is contributed by 29AjayKumar`

## C#

 `// C# program to find minimum number which divide n``// to make it a perfect cube``using` `System;` `class` `GFG{``  ` `// Returns the minimum divisor``static` `int` `findMinNumber(``int` `n)``{``    ``int` `count = 0, ans = 1;``  ` `    ``// Since 2 is only even prime, compute its``    ``// power separately.``    ``while` `(n % 2 == 0) {``        ``count++;``        ``n /= 2;``    ``}``  ` `    ``// If count is not divisible by 3, ``    ``// it must be removed by dividing``    ``// n by prime number power.``    ``if` `(count % 3 != 0)``        ``ans *= (``int``)Math.Pow(2, (count % 3));``  ` `    ``for` `(``int` `i = 3; i <= Math.Sqrt(n); i += 2) {``        ``count = 0;``        ``while` `(n % i == 0) {``            ``count++;``            ``n /= i;``        ``}``  ` `        ``// If count is not divisible by 3, ``        ``// it must be removed by dividing``        ``// n by prime number power.``        ``if` `(count % 3 != 0)``            ``ans *= (``int``)Math.Pow(i, (count % 3));``    ``}``  ` `    ``// if n is a prime number``    ``if` `(n > 2)``        ``ans *= n;``  ` `    ``return` `ans;``}``  ` `// Driver code``public` `static` `void` `Main(String[] args)``{``    ``int` `n = 128;``    ``Console.Write(findMinNumber(n) +``"\n"``);``}``}` `// This code is contributed by 29AjayKumar`

## Javascript

 ``

Output:
`2`

Time Complexity: O(sqrt(n))
Auxiliary Space: O(1)

Previous
Next