21876560 has 20 divisors (see below), whose sum is σ = 50863188. Its totient is φ = 8750592.

The previous prime is 21876553. The next prime is 21876587. The reversal of 21876560 is 6567812.

It can be written as a sum of positive squares in 2 ways, for example, as 15178816 + 6697744 = 3896^2 + 2588^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 21876560.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 136649 + ... + 136808.

Almost surely, 2^21876560 is an apocalyptic number.

21876560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21876560 is an abundant number, since it is smaller than the sum of its proper divisors (28986628).

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

21876560 is a wasteful number, since it uses less digits than its factorization.

21876560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273470 (or 273464 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 21876560 is about 4677.2385015092. The cubic root of 21876560 is about 279.6788835709.

The spelling of 21876560 in words is "twenty-one million, eight hundred seventy-six thousand, five hundred sixty".