Work out reverse a number instantly with clear inputs, formula shown and shareable results.
Reversing a number rewrites its digits in the opposite order. The difference between a number and its reverse is always a multiple of 9, because reversing permutes digits without changing their sum.
Reverse
write the decimal digits in reverse order; |v − reverse(v)| is divisible by 9
54321, and the difference 41976 is divisible by 9.
Repeatedly adding a number to its reverse usually reaches a palindrome; numbers where it appears never to do so, such as 196, are called Lychrel candidates.