204308809 has 4 divisors (see below), whose sum is σ = 205225216. Its totient is φ = 203392404.

The previous prime is 204308791. The next prime is 204308813. The reversal of 204308809 is 908803402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 204308809 - 2⁵ = 204308777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (204308849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 457869 + ... + 458314.

It is an arithmetic number, because the mean of its divisors is an integer number (51306304).

Almost surely, 2^204308809 is an apocalyptic number.

It is an amenable number.

204308809 is a deficient number, since it is larger than the sum of its proper divisors (916407).

204308809 is an equidigital number, since it uses as much as digits as its factorization.

204308809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916406.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 204308809 is about 14293.6632463480. The cubic root of 204308809 is about 588.9734221449.

The spelling of 204308809 in words is "two hundred four million, three hundred eight thousand, eight hundred nine".