It is a tau number, because it is divible by the number of its divisors (8).
It is a nialpdrome in base 14.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20456.
It is an unprimeable number.
220456 is an apocalyptic number.
It is an amenable number.
20456 is a wasteful number, since it uses less digits than its factorization.
20456 is an odious number, because the sum of its binary digits is odd.
The square root of 20456 is about 143.0244734302. The cubic root of 20456 is about 27.3489236197.
Adding to 20456 its reverse (65402), we get a palindrome (85858).
The spelling of 20456 in words is "twenty thousand, four hundred fifty-six".