205715 has 4 divisors (see below), whose sum is σ = 246864. Its totient is φ = 164568.

The previous prime is 205703. The next prime is 205721. The reversal of 205715 is 517502.

205715 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 205715 - 2⁶ = 205651 is a prime.

It is a super-2 number, since 2×205715² = 84637322450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20567 + ... + 20576.

It is an arithmetic number, because the mean of its divisors is an integer number (61716).

2²⁰⁵⁷¹⁵ is an apocalyptic number.

205715 is a deficient number, since it is larger than the sum of its proper divisors (41149).

205715 is an equidigital number, since it uses as much as digits as its factorization.

205715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41148.

The product of its (nonzero) digits is 350, while the sum is 20.

The square root of 205715 is about 453.5581550364. The cubic root of 205715 is about 59.0321571325.

The spelling of 205715 in words is "two hundred five thousand, seven hundred fifteen".