21800256 has 56 divisors (see below), whose sum is σ = 61081920. Its totient is φ = 6838272.

The previous prime is 21800237. The next prime is 21800281. The reversal of 21800256 is 65200812.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76 + ... + 6603.

Almost surely, 2^21800256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21800256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30540960).

21800256 is an abundant number, since it is smaller than the sum of its proper divisors (39281664).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21800256 is a wasteful number, since it uses less digits than its factorization.

21800256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6711 (or 6701 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 21800256 is about 4669.0744264790. The cubic root of 21800256 is about 279.3533376094.

The spelling of 21800256 in words is "twenty-one million, eight hundred thousand, two hundred fifty-six".