21903364 has 12 divisors (see below), whose sum is σ = 43806784. Its totient is φ = 9387144.

The previous prime is 21903359. The next prime is 21903379. The reversal of 21903364 is 46330912.

21903364 is an admirable number.

It is a Harshad number since it is a multiple of its sum of digits (28), and also a Moran number because the ratio is a prime number: 782263 = 21903364 / (2 + 1 + 9 + 0 + 3 + 3 + 6 + 4).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 391104 + ... + 391159.

Almost surely, 2^21903364 is an apocalyptic number.

It is an amenable number.

21903364 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21903364 is a wasteful number, since it uses less digits than its factorization.

21903364 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 782274 (or 782272 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 21903364 is about 4680.1029903198. The cubic root of 21903364 is about 279.7930613820.

The spelling of 21903364 in words is "twenty-one million, nine hundred three thousand, three hundred sixty-four".