21885872 has 20 divisors (see below), whose sum is σ = 44636280. Its totient is φ = 10366848.

The previous prime is 21885869. The next prime is 21885881. The reversal of 21885872 is 27858812.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

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, 35693 + ... + 36300.

It is an arithmetic number, because the mean of its divisors is an integer number (2231814).

Almost surely, 2^21885872 is an apocalyptic number.

It is an amenable number.

21885872 is an abundant number, since it is smaller than the sum of its proper divisors (22750408).

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

21885872 is a wasteful number, since it uses less digits than its factorization.

21885872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72020 (or 72014 counting only the distinct ones).

The product of its digits is 71680, while the sum is 41.

The square root of 21885872 is about 4678.2338547790. The cubic root of 21885872 is about 279.7185607463.

The spelling of 21885872 in words is "twenty-one million, eight hundred eighty-five thousand, eight hundred seventy-two".