205858 has 4 divisors (see below), whose sum is σ = 308790. Its totient is φ = 102928.

The previous prime is 205847. The next prime is 205879. The reversal of 205858 is 858502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 117649 + 88209 = 343^2 + 297^2 .

It is an unprimeable number.

205858 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 as a sum of consecutive naturals, namely, 51463 + ... + 51466.

2²⁰⁵⁸⁵⁸ is an apocalyptic number.

205858 is a deficient number, since it is larger than the sum of its proper divisors (102932).

205858 is a wasteful number, since it uses less digits than its factorization.

205858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102931.

The product of its (nonzero) digits is 3200, while the sum is 28.

The square root of 205858 is about 453.7157700587. The cubic root of 205858 is about 59.0458324328.

It can be divided in two parts, 2058 and 58, that added together give a square (2116 = 46²).

The spelling of 205858 in words is "two hundred five thousand, eight hundred fifty-eight".