205290 has 24 divisors (see below), whose sum is σ = 533988. Its totient is φ = 54720.

The previous prime is 205267. The next prime is 205297. The reversal of 205290 is 92502.

205290 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 205209 + 81 = 453^2 + 9^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205297) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1051 + ... + 1230.

2²⁰⁵²⁹⁰ is an apocalyptic number.

205290 is an abundant number, since it is smaller than the sum of its proper divisors (328698).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

205290 is a wasteful number, since it uses less digits than its factorization.

205290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2294 (or 2291 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 205290 is about 453.0893951529. The cubic root of 205290 is about 58.9914763134.

Adding to 205290 its reverse (92502), we get a palindrome (297792).

The spelling of 205290 in words is "two hundred five thousand, two hundred ninety".