21088504 has 8 divisors (see below), whose sum is σ = 39540960. Its totient is φ = 10544248.

The previous prime is 21088469. The next prime is 21088513. The reversal of 21088504 is 40588012.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

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 as a sum of consecutive naturals, namely, 1318024 + ... + 1318039.

It is an arithmetic number, because the mean of its divisors is an integer number (4942620).

Almost surely, 2^21088504 is an apocalyptic number.

It is an amenable number.

21088504 is a deficient number, since it is larger than the sum of its proper divisors (18452456).

21088504 is a wasteful number, since it uses less digits than its factorization.

21088504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2636069 (or 2636065 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 28.

The square root of 21088504 is about 4592.2221200634. Note that the first 3 decimals coincide. The cubic root of 21088504 is about 276.2794551013.

The spelling of 21088504 in words is "twenty-one million, eighty-eight thousand, five hundred four".