21046388 has 24 divisors (see below), whose sum is σ = 40751424. Its totient is φ = 9430400.

The previous prime is 21046387. The next prime is 21046409. The reversal of 21046388 is 88364012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21046387) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 245 + ... + 6492.

It is an arithmetic number, because the mean of its divisors is an integer number (1697976).

Almost surely, 2^21046388 is an apocalyptic number.

It is an amenable number.

21046388 is a deficient number, since it is larger than the sum of its proper divisors (19705036).

21046388 is a wasteful number, since it uses less digits than its factorization.

21046388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6823 (or 6821 counting only the distinct ones).

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

The square root of 21046388 is about 4587.6342487169. The cubic root of 21046388 is about 276.0954126469.

The spelling of 21046388 in words is "twenty-one million, forty-six thousand, three hundred eighty-eight".