405904 has 20 divisors (see below), whose sum is σ = 821376. Its totient is φ = 193952.

The previous prime is 405901. The next prime is 405917. The reversal of 405904 is 409504.

It is not an unprimeable number, because it can be changed into a prime (405901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 184 + ... + 919.

2⁴⁰⁵⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

405904 is an abundant number, since it is smaller than the sum of its proper divisors (415472).

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

405904 is a wasteful number, since it uses less digits than its factorization.

405904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1134 (or 1128 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 405904 is about 637.1059566509. The cubic root of 405904 is about 74.0413696122.

Subtracting 405904 from its reverse (409504), we obtain a square (3600 = 60²).

The spelling of 405904 in words is "four hundred five thousand, nine hundred four".