21164204 has 6 divisors (see below), whose sum is σ = 37037364. Its totient is φ = 10582100.

The previous prime is 21164189. The next prime is 21164237. The reversal of 21164204 is 40246112.

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, 2645522 + ... + 2645529.

It is an arithmetic number, because the mean of its divisors is an integer number (6172894).

Almost surely, 2^21164204 is an apocalyptic number.

It is an amenable number.

21164204 is a deficient number, since it is larger than the sum of its proper divisors (15873160).

21164204 is a wasteful number, since it uses less digits than its factorization.

21164204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5291055 (or 5291053 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21164204 is about 4600.4569338273. The cubic root of 21164204 is about 276.6096409944.

The spelling of 21164204 in words is "twenty-one million, one hundred sixty-four thousand, two hundred four".