204009 has 8 divisors (see below), whose sum is σ = 292992. Its totient is φ = 125520.

The previous prime is 204007. The next prime is 204013. The reversal of 204009 is 900402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 204009 - 2¹ = 204007 is a prime.

It is an Ulam number.

It is a Curzon number.

204009 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (204007) 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, 2577 + ... + 2654.

It is an arithmetic number, because the mean of its divisors is an integer number (36624).

2²⁰⁴⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

204009 is a deficient number, since it is larger than the sum of its proper divisors (88983).

204009 is a wasteful number, since it uses less digits than its factorization.

204009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5247.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 204009 is about 451.6735546830. The cubic root of 204009 is about 58.8685188569.

The spelling of 204009 in words is "two hundred four thousand, nine".