21385804 has 12 divisors (see below), whose sum is σ = 40827528. Its totient is φ = 9720800.

The previous prime is 21385801. The next prime is 21385817. The reversal of 21385804 is 40858312.

It is a super-2 number, since 2×21385804² = 914705225452832, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21385801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242977 + ... + 243064.

It is an arithmetic number, because the mean of its divisors is an integer number (3402294).

Almost surely, 2^21385804 is an apocalyptic number.

It is an amenable number.

21385804 is a deficient number, since it is larger than the sum of its proper divisors (19441724).

21385804 is a wasteful number, since it uses less digits than its factorization.

21385804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486056 (or 486054 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 21385804 is about 4624.4787814412. The cubic root of 21385804 is about 277.5717056264.

The spelling of 21385804 in words is "twenty-one million, three hundred eighty-five thousand, eight hundred four".