204408809 has 12 divisors (see below), whose sum is σ = 225870708. Its totient is φ = 184842240.

The previous prime is 204408769. The next prime is 204408811. The reversal of 204408809 is 908804402.

It can be written as a sum of positive squares in 2 ways, for example, as 117397225 + 87011584 = 10835^2 + 9328^2 .

It is not a de Polignac number, because 204408809 - 2⁸ = 204408553 is a prime.

It is a super-2 number, since 2×204408809² = 83565922393596962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204408829) 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, 18977 + ... + 27729.

It is an arithmetic number, because the mean of its divisors is an integer number (18822559).

Almost surely, 2^204408809 is an apocalyptic number.

It is an amenable number.

204408809 is a deficient number, since it is larger than the sum of its proper divisors (21461899).

204408809 is a wasteful number, since it uses less digits than its factorization.

204408809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8968 (or 8957 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 204408809 is about 14297.1608720053. The cubic root of 204408809 is about 589.0694984977.

The spelling of 204408809 in words is "two hundred four million, four hundred eight thousand, eight hundred nine".