21803684 has 24 divisors (see below), whose sum is σ = 44163840. Its totient is φ = 9225216.

The previous prime is 21803671. The next prime is 21803729. The reversal of 21803684 is 48630812.

It is a self number, because there is not a number n which added to its sum of digits gives 21803684.

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, 2717 + ... + 7140.

It is an arithmetic number, because the mean of its divisors is an integer number (1840160).

Almost surely, 2^21803684 is an apocalyptic number.

It is an amenable number.

21803684 is an abundant number, since it is smaller than the sum of its proper divisors (22360156).

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

21803684 is a wasteful number, since it uses less digits than its factorization.

21803684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9947 (or 9945 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 21803684 is about 4669.4415083605. The cubic root of 21803684 is about 279.3679792272.

The spelling of 21803684 in words is "twenty-one million, eight hundred three thousand, six hundred eighty-four".