204005 has 4 divisors (see below), whose sum is σ = 244812. Its totient is φ = 163200.

The previous prime is 203999. The next prime is 204007. The reversal of 204005 is 500402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 145924 + 58081 = 382^2 + 241^2 .

It is not a de Polignac number, because 204005 - 2⁴ = 203989 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent 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 3 ways as a sum of consecutive naturals, for example, 20396 + ... + 20405.

It is an arithmetic number, because the mean of its divisors is an integer number (61203).

2²⁰⁴⁰⁰⁵ is an apocalyptic number.

It is an amenable number.

204005 is a deficient number, since it is larger than the sum of its proper divisors (40807).

204005 is an equidigital number, since it uses as much as digits as its factorization.

204005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40806.

The product of its (nonzero) digits is 40, while the sum is 11.

The square root of 204005 is about 451.6691266846. The cubic root of 204005 is about 58.8681341098.

Adding to 204005 its reverse (500402), we get a palindrome (704407).

The spelling of 204005 in words is "two hundred four thousand, five".