820839904 has 12 divisors (see below), whose sum is σ = 1616028624. Its totient is φ = 410419936.

The previous prime is 820839853. The next prime is 820839911. The reversal of 820839904 is 409938028.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 12825592 + ... + 12825655.

It is an arithmetic number, because the mean of its divisors is an integer number (134669052).

Almost surely, 2^820839904 is an apocalyptic number.

It is an amenable number.

820839904 is a deficient number, since it is larger than the sum of its proper divisors (795188720).

820839904 is a wasteful number, since it uses less digits than its factorization.

820839904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25651257 (or 25651249 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 820839904 is about 28650.3037331195. The cubic root of 820839904 is about 936.3096231377.

The spelling of 820839904 in words is "eight hundred twenty million, eight hundred thirty-nine thousand, nine hundred four".