205915 has 4 divisors (see below), whose sum is σ = 247104. Its totient is φ = 164728.

The previous prime is 205913. The next prime is 205937. The reversal of 205915 is 519502.

205915 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, and also an emirpimes, since its reverse is a distinct semiprime: 519502 = 2 ⋅259751.

It is a cyclic number.

It is not a de Polignac number, because 205915 - 2¹ = 205913 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205913) 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, 20587 + ... + 20596.

It is an arithmetic number, because the mean of its divisors is an integer number (61776).

2²⁰⁵⁹¹⁵ is an apocalyptic number.

205915 is a deficient number, since it is larger than the sum of its proper divisors (41189).

205915 is an equidigital number, since it uses as much as digits as its factorization.

205915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41188.

The product of its (nonzero) digits is 450, while the sum is 22.

The square root of 205915 is about 453.7785803671. The cubic root of 205915 is about 59.0512816613.

The spelling of 205915 in words is "two hundred five thousand, nine hundred fifteen".