205890 has 16 divisors (see below), whose sum is σ = 494208. Its totient is φ = 54896.

The previous prime is 205883. The next prime is 205913. The reversal of 205890 is 98502.

It is a self number, because there is not a number n which added to its sum of digits gives 205890.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3402 + ... + 3461.

It is an arithmetic number, because the mean of its divisors is an integer number (30888).

2²⁰⁵⁸⁹⁰ is an apocalyptic number.

205890 is an abundant number, since it is smaller than the sum of its proper divisors (288318).

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

205890 is a wasteful number, since it uses less digits than its factorization.

205890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6873.

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 205890 is about 453.7510330567. The cubic root of 205890 is about 59.0488917726.

The spelling of 205890 in words is "two hundred five thousand, eight hundred ninety".