205790 has 16 divisors (see below), whose sum is σ = 399168. Its totient is φ = 75936.

The previous prime is 205783. The next prime is 205817. The reversal of 205790 is 97502.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 662 + ... + 921.

It is an arithmetic number, because the mean of its divisors is an integer number (24948).

2²⁰⁵⁷⁹⁰ is an apocalyptic number.

205790 is a deficient number, since it is larger than the sum of its proper divisors (193378).

205790 is a wasteful number, since it uses less digits than its factorization.

205790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603.

The product of its (nonzero) digits is 630, while the sum is 23.

The square root of 205790 is about 453.6408270868. The cubic root of 205790 is about 59.0393302828.

The spelling of 205790 in words is "two hundred five thousand, seven hundred ninety".