205705 has 4 divisors (see below), whose sum is σ = 246852. Its totient is φ = 164560.

The previous prime is 205703. The next prime is 205721. The reversal of 205705 is 507502.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 507502 = 2 ⋅253751.

It can be written as a sum of positive squares in 2 ways, for example, as 95481 + 110224 = 309^2 + 332^2 .

It is not a de Polignac number, because 205705 - 2¹ = 205703 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20566 + ... + 20575.

It is an arithmetic number, because the mean of its divisors is an integer number (61713).

2²⁰⁵⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

205705 is a deficient number, since it is larger than the sum of its proper divisors (41147).

205705 is an equidigital number, since it uses as much as digits as its factorization.

205705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41146.

The product of its (nonzero) digits is 350, while the sum is 19.

The square root of 205705 is about 453.5471309577. The cubic root of 205705 is about 59.0312005807.

The spelling of 205705 in words is "two hundred five thousand, seven hundred five".