21866875 has 20 divisors (see below), whose sum is σ = 27834840. Its totient is φ = 17168000.

The previous prime is 21866861. The next prime is 21866893. The reversal of 21866875 is 57866812.

It is not a de Polignac number, because 21866875 - 2⁵ = 21866843 is a prime.

Its product of digits (161280) is a multiple of the sum of its prime factors (672).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 36579 + ... + 37171.

It is an arithmetic number, because the mean of its divisors is an integer number (1391742).

Almost surely, 2^21866875 is an apocalyptic number.

21866875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21866875 is a deficient number, since it is larger than the sum of its proper divisors (5967965).

21866875 is an frugal number, since it uses more digits than its factorization.

21866875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672 (or 657 counting only the distinct ones).

The product of its digits is 161280, while the sum is 43.

The square root of 21866875 is about 4676.2030537606. The cubic root of 21866875 is about 279.6376051461.

The spelling of 21866875 in words is "twenty-one million, eight hundred sixty-six thousand, eight hundred seventy-five".