21885020 has 24 divisors (see below), whose sum is σ = 46384800. Its totient is φ = 8672832.

The previous prime is 21885013. The next prime is 21885023. The reversal of 21885020 is 2058812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21885023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2840 + ... + 7199.

It is an arithmetic number, because the mean of its divisors is an integer number (1932700).

Almost surely, 2^21885020 is an apocalyptic number.

21885020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21885020 is an abundant number, since it is smaller than the sum of its proper divisors (24499780).

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

21885020 is a wasteful number, since it uses less digits than its factorization.

21885020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10157 (or 10155 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 21885020 is about 4678.1427938873. The cubic root of 21885020 is about 279.7149309571.

The spelling of 21885020 in words is "twenty-one million, eight hundred eighty-five thousand, twenty".