205604 has 18 divisors (see below), whose sum is σ = 418950. Its totient is φ = 88032.

The previous prime is 205603. The next prime is 205607. The reversal of 205604 is 406502.

It can be written as a sum of positive squares in only one way, i.e., 200704 + 4900 = 448^2 + 70^2 .

It is not an unprimeable number, because it can be changed into a prime (205603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 329 + ... + 720.

It is an arithmetic number, because the mean of its divisors is an integer number (23275).

2²⁰⁵⁶⁰⁴ is an apocalyptic number.

It is an amenable number.

205604 is an abundant number, since it is smaller than the sum of its proper divisors (213346).

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

205604 is a wasteful number, since it uses less digits than its factorization.

205604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1067 (or 1058 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 205604 is about 453.4357727396. The cubic root of 205604 is about 59.0215376697.

The spelling of 205604 in words is "two hundred five thousand, six hundred four".