21882164 has 12 divisors (see below), whose sum is σ = 38921988. Its totient is φ = 10761600.

The previous prime is 21882149. The next prime is 21882181. The reversal of 21882164 is 46128812.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6041764 + 15840400 = 2458^2 + 3980^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21882164.

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, 44597 + ... + 45084.

It is an arithmetic number, because the mean of its divisors is an integer number (3243499).

Almost surely, 2^21882164 is an apocalyptic number.

It is an amenable number.

21882164 is a deficient number, since it is larger than the sum of its proper divisors (17039824).

21882164 is a wasteful number, since it uses less digits than its factorization.

21882164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89746 (or 89744 counting only the distinct ones).

The product of its digits is 6144, while the sum is 32.

The square root of 21882164 is about 4677.8375345880. The cubic root of 21882164 is about 279.7027628074.

The spelling of 21882164 in words is "twenty-one million, eight hundred eighty-two thousand, one hundred sixty-four".