205904 has 20 divisors (see below), whose sum is σ = 422964. Its totient is φ = 96768.

The previous prime is 205883. The next prime is 205913. The reversal of 205904 is 409502.

It can be written as a sum of positive squares in 2 ways, for example, as 144400 + 61504 = 380^2 + 248^2 .

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 205904.

It is an unprimeable number.

205904 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, 107 + ... + 650.

2²⁰⁵⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

205904 is an abundant number, since it is smaller than the sum of its proper divisors (217060).

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

205904 is a wasteful number, since it uses less digits than its factorization.

205904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782 (or 776 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 205904 is about 453.7664597566. The cubic root of 205904 is about 59.0502301341.

The spelling of 205904 in words is "two hundred five thousand, nine hundred four".