205389 has 8 divisors (see below), whose sum is σ = 304320. Its totient is φ = 136908.

The previous prime is 205357. The next prime is 205391. The reversal of 205389 is 983502.

It is not a de Polignac number, because 205389 - 2⁵ = 205357 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 7607 = 205389 / (2 + 0 + 5 + 3 + 8 + 9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205319) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3777 + ... + 3830.

It is an arithmetic number, because the mean of its divisors is an integer number (38040).

205389 is a Friedman number, since it can be written as 59^3+8+2+0, using all its digits and the basic arithmetic operations.

2²⁰⁵³⁸⁹ is an apocalyptic number.

It is an amenable number.

205389 is a deficient number, since it is larger than the sum of its proper divisors (98931).

205389 is an equidigital number, since it uses as much as digits as its factorization.

205389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7616 (or 7610 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 205389 is about 453.1986319485. The cubic root of 205389 is about 59.0009575637. Note that the first 3 decimals are identical.

The spelling of 205389 in words is "two hundred five thousand, three hundred eighty-nine".