205545 has 16 divisors (see below), whose sum is σ = 335232. Its totient is φ = 107520.

The previous prime is 205537. The next prime is 205549. The reversal of 205545 is 545502.

205545 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 205545 - 2³ = 205537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205549) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 969 + ... + 1161.

It is an arithmetic number, because the mean of its divisors is an integer number (20952).

2²⁰⁵⁵⁴⁵ is an apocalyptic number.

It is an amenable number.

205545 is a deficient number, since it is larger than the sum of its proper divisors (129687).

205545 is a wasteful number, since it uses less digits than its factorization.

205545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272.

The product of its (nonzero) digits is 1000, while the sum is 21.

The square root of 205545 is about 453.3707092436. The cubic root of 205545 is about 59.0158915346.

It can be divided in two parts, 20 and 5545, that added together give a triangular number (5565 = T₁₀₅).

The spelling of 205545 in words is "two hundred five thousand, five hundred forty-five".