How this calculation works
Check whether a whole number reads the same in both directions.
THE FORMULA
Reverse the decimal digits and compare the two stringsA worked example
12321 remains unchanged when reversed.
Good to know
Initial zeros are outside the whole-number representation.
Reference: NIST DLMF, Functions of Number Theory (opens in a new tab) ↗
Read the result
Check whether a whole number reads the same in both directions.
The primary result is labeled “Palindrome?”. Keep the input definitions in view when comparing this result with another method.
Try a related calculation
Initial zeros are outside the whole-number representation.
For a related exercise, try the greatest common divisor.
A few questions, answered
How can I check the default inputs by hand?
12321 remains unchanged when reversed.
Which rule does this calculator apply?
Reverse the decimal digits and compare the two strings