21854556 has 24 divisors (see below), whose sum is σ = 56660240. Its totient is φ = 7284816.

The previous prime is 21854543. The next prime is 21854561. The reversal of 21854556 is 65545812.

21854556 is a `hidden beast` number, since 21 + 85 + 4 + 556 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21854556.

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, 101071 + ... + 101286.

Almost surely, 2^21854556 is an apocalyptic number.

It is an amenable number.

21854556 is an abundant number, since it is smaller than the sum of its proper divisors (34805684).

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

21854556 is a wasteful number, since it uses less digits than its factorization.

21854556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202370 (or 202362 counting only the distinct ones).

The product of its digits is 48000, while the sum is 36.

The square root of 21854556 is about 4674.8856670511. The cubic root of 21854556 is about 279.5850827386.

The spelling of 21854556 in words is "twenty-one million, eight hundred fifty-four thousand, five hundred fifty-six".