821004804 has 36 divisors (see below), whose sum is σ = 2076197760. Its totient is φ = 273552240.

The previous prime is 821004773. The next prime is 821004809. The reversal of 821004804 is 408400128.

821004804 is a `hidden beast` number, since 82 + 100 + 480 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (821004809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 144049 + ... + 149639.

It is an arithmetic number, because the mean of its divisors is an integer number (57672160).

Almost surely, 2^821004804 is an apocalyptic number.

It is an amenable number.

821004804 is an abundant number, since it is smaller than the sum of its proper divisors (1255192956).

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

821004804 is a wasteful number, since it uses less digits than its factorization.

821004804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9680 (or 9675 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 821004804 is about 28653.1813940442. The cubic root of 821004804 is about 936.3723179125.

The spelling of 821004804 in words is "eight hundred twenty-one million, four thousand, eight hundred four".