21904875 has 24 divisors (see below), whose sum is σ = 39489216. Its totient is φ = 11682000.

The previous prime is 21904873. The next prime is 21904877. The reversal of 21904875 is 57840912.

It is an interprime number because it is at equal distance from previous prime (21904873) and next prime (21904877).

It is not a de Polignac number, because 21904875 - 2¹ = 21904873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21904873) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8611 + ... + 10860.

It is an arithmetic number, because the mean of its divisors is an integer number (1645384).

Almost surely, 2^21904875 is an apocalyptic number.

21904875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21904875 is a deficient number, since it is larger than the sum of its proper divisors (17584341).

21904875 is a wasteful number, since it uses less digits than its factorization.

21904875 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19492 (or 19479 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 21904875 is about 4680.2644156073. The cubic root of 21904875 is about 279.7994950603.

The spelling of 21904875 in words is "twenty-one million, nine hundred four thousand, eight hundred seventy-five".