205864 has 8 divisors (see below), whose sum is σ = 386010. Its totient is φ = 102928.

The previous prime is 205847. The next prime is 205879. The reversal of 205864 is 468502.

It can be written as a sum of positive squares in only one way, i.e., 202500 + 3364 = 450^2 + 58^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12859 + ... + 12874.

2²⁰⁵⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

205864 is a deficient number, since it is larger than the sum of its proper divisors (180146).

205864 is a wasteful number, since it uses less digits than its factorization.

205864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25739 (or 25735 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 205864 is about 453.7223820796. The cubic root of 205864 is about 59.0464060831.

The spelling of 205864 in words is "two hundred five thousand, eight hundred sixty-four".