391804 has 18 divisors (see below), whose sum is σ = 798000. Its totient is φ = 167832.

The previous prime is 391801. The next prime is 391817. The reversal of 391804 is 408193.

391804 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391801) 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 5 ways as a sum of consecutive naturals, for example, 804 + ... + 1195.

2³⁹¹⁸⁰⁴ is an apocalyptic number.

It is an amenable number.

391804 is an abundant number, since it is smaller than the sum of its proper divisors (406196).

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

391804 is a wasteful number, since it uses less digits than its factorization.

391804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2017 (or 2008 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 391804 is about 625.9424893710. The cubic root of 391804 is about 73.1739144812.

Adding to 391804 its reverse (408193), we get a palindrome (799997).

The spelling of 391804 in words is "three hundred ninety-one thousand, eight hundred four".