A palindromic number is number that remains the same when its digits are reversed.
Here's how to check if a number is a palindrome:
Take the original number and reverse it.
Here is the original number color coded:
Now we reverse it like this:
Notice the colors are going in the opposite direction now
Compare the two numbers. If they are exactly the same then the number is a palindrome.
Is 542155 = 551245?
NO, so that means the number 542,155 is not a palindrome!
Here are more examples of potential palindrome numbers in sequence: