204990 has 16 divisors (see below), whose sum is σ = 492048. Its totient is φ = 54656.

The previous prime is 204983. The next prime is 205019. The reversal of 204990 is 99402.

204990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 204990.

It is a congruent number.

It is an unprimeable number.

204990 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3387 + ... + 3446.

It is an arithmetic number, because the mean of its divisors is an integer number (30753).

2²⁰⁴⁹⁹⁰ is an apocalyptic number.

204990 is an abundant number, since it is smaller than the sum of its proper divisors (287058).

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

204990 is a wasteful number, since it uses less digits than its factorization.

204990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6843.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 204990 is about 452.7582136196. The cubic root of 204990 is about 58.9627266250.

The spelling of 204990 in words is "two hundred four thousand, nine hundred ninety".