21856328 has 16 divisors (see below), whose sum is σ = 44133180. Its totient is φ = 10087488.

The previous prime is 21856277. The next prime is 21856337. The reversal of 21856328 is 82365812.

It can be written as a sum of positive squares in 2 ways, for example, as 20811844 + 1044484 = 4562^2 + 1022^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104975 + ... + 105182.

Almost surely, 2^21856328 is an apocalyptic number.

It is an amenable number.

21856328 is an abundant number, since it is smaller than the sum of its proper divisors (22276852).

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

21856328 is a wasteful number, since it uses less digits than its factorization.

21856328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210176 (or 210172 counting only the distinct ones).

The product of its digits is 23040, while the sum is 35.

The square root of 21856328 is about 4675.0751865612. The cubic root of 21856328 is about 279.5926389262.

The spelling of 21856328 in words is "twenty-one million, eight hundred fifty-six thousand, three hundred twenty-eight".