21859344 has 60 divisors (see below), whose sum is σ = 65887276. Its totient is φ = 6725376.

The previous prime is 21859337. The next prime is 21859349. The reversal of 21859344 is 44395812.

21859344 is a `hidden beast` number, since 21 + 8 + 593 + 44 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 10969344 + 10890000 = 3312^2 + 3300^2 .

It is a super-2 number, since 2×21859344² = 955661840220672, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 21859299 and 21859308.

It is not an unprimeable number, because it can be changed into a prime (21859349) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3967 + ... + 7710.

Almost surely, 2^21859344 is an apocalyptic number.

21859344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21859344 is an abundant number, since it is smaller than the sum of its proper divisors (44027932).

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

21859344 is a wasteful number, since it uses less digits than its factorization.

21859344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11704 (or 11695 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 21859344 is about 4675.3977370915. The cubic root of 21859344 is about 279.6054988573.

The spelling of 21859344 in words is "twenty-one million, eight hundred fifty-nine thousand, three hundred forty-four".