Given a number N containing even number of digits. The task is to check whether that number is palindrome or not.
Input: N = 123321 Output: Palindrome Input: 1234 Output: Not palindrome
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.
- Count the number of digits of palindrome numbers in an array
- Check whether product of digits at even places is divisible by sum of digits at odd place of a number
- Check if a number is Palindrome
- Check if a number is Palindrome in PL/SQL
- Check if number is palindrome or not in Octal
- Program to check the number is Palindrome or not
- Bash program to check if the Number is a Palindrome
- Recursive program to check if number is palindrome or not
- Check if binary representation of a number is palindrome
- Generate number with given operation and check if it is palindrome
- To check a number is palindrome or not without using any extra space
- Check if actual binary representation of a number is palindrome
- Check if two numbers have same number of digits
- Check if the frequency of all the digits in a number is same
- Check if the Xor of the frequency of all digits of a number N is zero or not
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to firstname.lastname@example.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.