204136909 has 8 divisors (see below), whose sum is σ = 209841912. Its totient is φ = 198466560.

The previous prime is 204136903. The next prime is 204136913. The reversal of 204136909 is 909631402.

204136909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 6874884 + 197262025 = 2622^2 + 14045^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 204136909 - 2¹⁵ = 204104141 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204136903) 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, 3517 + ... + 20509.

It is an arithmetic number, because the mean of its divisors is an integer number (26230239).

Almost surely, 2^204136909 is an apocalyptic number.

It is an amenable number.

204136909 is a deficient number, since it is larger than the sum of its proper divisors (5705003).

204136909 is a wasteful number, since it uses less digits than its factorization.

204136909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17327.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 204136909 is about 14287.6488268714. The cubic root of 204136909 is about 588.8081936038.

The spelling of 204136909 in words is "two hundred four million, one hundred thirty-six thousand, nine hundred nine".