399804 has 12 divisors (see below), whose sum is σ = 932904. Its totient is φ = 133264.

The previous prime is 399793. The next prime is 399851. The reversal of 399804 is 408993.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

399804 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16647 + ... + 16670.

It is an arithmetic number, because the mean of its divisors is an integer number (77742).

2³⁹⁹⁸⁰⁴ is an apocalyptic number.

It is an amenable number.

399804 is an abundant number, since it is smaller than the sum of its proper divisors (533100).

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

399804 is a wasteful number, since it uses less digits than its factorization.

399804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33324 (or 33322 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 399804 is about 632.3005614421. The cubic root of 399804 is about 73.6685935037.

The spelling of 399804 in words is "three hundred ninety-nine thousand, eight hundred four".