21165084 has 24 divisors (see below), whose sum is σ = 54872720. Its totient is φ = 7054992.

The previous prime is 21165077. The next prime is 21165097. The reversal of 21165084 is 48056112.

21165084 is a `hidden beast` number, since 2 + 1 + 1 + 650 + 8 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97879 + ... + 98094.

Almost surely, 2^21165084 is an apocalyptic number.

It is an amenable number.

21165084 is an abundant number, since it is smaller than the sum of its proper divisors (33707636).

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

21165084 is a wasteful number, since it uses less digits than its factorization.

21165084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195986 (or 195978 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 21165084 is about 4600.5525755066. The cubic root of 21165084 is about 276.6134747178.

The spelling of 21165084 in words is "twenty-one million, one hundred sixty-five thousand, eighty-four".