204534509 has 2 divisors, whose sum is σ = 204534510. Its totient is φ = 204534508.

The previous prime is 204534481. The next prime is 204534511. The reversal of 204534509 is 905435402.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167055625 + 37478884 = 12925^2 + 6122^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204534509 is a prime.

Together with 204534511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (204534569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102267254 + 102267255.

It is an arithmetic number, because the mean of its divisors is an integer number (102267255).

Almost surely, 2^204534509 is an apocalyptic number.

It is an amenable number.

204534509 is a deficient number, since it is larger than the sum of its proper divisors (1).

204534509 is an equidigital number, since it uses as much as digits as its factorization.

204534509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 204534509 is about 14301.5561740672. The cubic root of 204534509 is about 589.1902220345.

The spelling of 204534509 in words is "two hundred four million, five hundred thirty-four thousand, five hundred nine".