21500868 has 12 divisors (see below), whose sum is σ = 50168720. Its totient is φ = 7166952.

The previous prime is 21500833. The next prime is 21500893. The reversal of 21500868 is 86800512.

It is a tau number, because it is divible by the number of its divisors (12).

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, 895858 + ... + 895881.

Almost surely, 2^21500868 is an apocalyptic number.

It is an amenable number.

21500868 is an abundant number, since it is smaller than the sum of its proper divisors (28667852).

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

21500868 is a wasteful number, since it uses less digits than its factorization.

21500868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1791746 (or 1791744 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 21500868 is about 4636.9028456503. The cubic root of 21500868 is about 278.0686302962.

The spelling of 21500868 in words is "twenty-one million, five hundred thousand, eight hundred sixty-eight".