# Check if a number with even number of digits is palindrome or not

Given a number N containing even number of digits. The task is to check whether that number is palindrome or not.

Examples:

```Input: N = 123321
Output: Palindrome

Input: 1234
Output: Not palindrome
```

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

A Naive Approach is to traverse from front and back of that number and stop where they do not match.

An Efficient Approach is to use the below fact:

Palindrome Number having even number of digits is always divisible by 11.

Suppose the number is d1 d2 d3 d4…dn, whered1, d2, d3.. are digits of a number. If it is a palindrome then d1 = dn, d2 = dn-1, d3 = dn-2…..and so on. Now since divisibility of 11 states that the difference of sum of alternate digits of a number should be zero and same in the case of palindrome having even no. of digits i.e.

d1 + d3 + …+ dn-1 = d2 + d4 + d6 + … + dn

So, a palindromic number having even number of digits is always divisible by 11.

## C++

 `// C++ program to find number is palindrome ` `// or not without using any extra space ` `#include ` `using` `namespace` `std; ` ` `  `// Function to check if the number is palindrome ` `bool` `isPalindrome(``int` `n) ` `{ ` `    ``// if divisible by 11 then true ` `    ``if` `(n % 11 == 0) { ` `        ``return` `true``; ` `    ``} ` ` `  `    ``// if not divisible by 11 ` `    ``return` `false``; ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``isPalindrome(123321) ? cout << ``"Palindrome"` `                         ``: cout << ``"Not Palindrome"``; ` `    ``return` `0; ` `} `

## Java

 `// Java program to find number ` `// is palindrome or not without  ` `// using any extra space  ` `class` `GFG  ` `{ ` `    ``// Function to check if the  ` `    ``// number is palindrome ` `    ``static` `boolean` `isPalindrome(``int` `n)  ` `    ``{  ` `        ``// if divisible by 11 then true  ` `        ``if` `(n % ``11` `== ``0``)  ` `        ``{  ` `            ``return` `true``;  ` `        ``}  ` `     `  `        ``// if not divisible by 11  ` `        ``return` `false``;  ` `    ``}  ` `     `  `    ``// Driver code  ` `    ``public` `static` `void` `main(String[] args)  ` `    ``{ ` `        ``System.out.println(isPalindrome(``123321``) ?  ` `                                   ``"Palindrome"` `:  ` `                               ``"Not Palindrome"``); ` `    ``} ` `} ` ` `  `// This code is contributed by Bilal `

## Python3

 `# Python 3 program to find number is palindrome  ` `# or not without using any extra space. ` ` `  `# Function to check if the number is palindrome  ` `def` `isPalindrome(n) : ` ` `  `    ``# if divisible by 11 then return True  ` `    ``if` `n ``%` `11` `=``=` `0` `: ` `        ``return` `True` ` `  `    ``# if not divisible by 11 then return False ` `    ``return` `False` ` `  `# Driver code ` `if` `__name__ ``=``=` `"__main__"` `: ` ` `  `    ``n ``=` `123321` `      `  `    ``if` `isPalindrome(n) : ` `        ``print``(``"Palindrome"``) ` `    ``else` `: ` `        ``print``(``"Not Palindrome"``) ` `             `  `# This code is contributed by ANKITRAI1 `

## C#

 `// C# program to find number ` `// is palindrome or not without  ` `// using any extra space  ` `using` `System; ` ` `  `class` `GFG  ` `{ ` `    ``// Function to check if the  ` `    ``// number is palindrome ` `    ``static` `bool` `isPalindrome(``int` `n)  ` `    ``{  ` `        ``// if divisible by  ` `        ``// 11 then true  ` `        ``if` `(n % 11 == 0)  ` `        ``{  ` `            ``return` `true``;  ` `        ``}  ` `     `  `        ``// if not divisible by 11  ` `        ``return` `false``;  ` `    ``}  ` `     `  `    ``// Driver code  ` `    ``public` `static` `void` `Main()  ` `    ``{ ` `        ``Console.Write(isPalindrome(123321) ?  ` `                              ``"Palindrome"` `:  ` `                          ``"Not Palindrome"``); ` `    ``} ` `} ` ` `  `// This code is contributed ` `// by ChitraNayal `

## PHP

 ` `

Output:

```Palindrome
```

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