204012509 has 2 divisors, whose sum is σ = 204012510. Its totient is φ = 204012508.

The previous prime is 204012493. The next prime is 204012517. The reversal of 204012509 is 905210402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165199609 + 38812900 = 12853^2 + 6230^2 .

It is a cyclic number.

It is not a de Polignac number, because 204012509 - 2⁴ = 204012493 is a prime.

It is a super-2 number, since 2×204012509² = 83242207656950162, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (200012509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102006254 + 102006255.

It is an arithmetic number, because the mean of its divisors is an integer number (102006255).

Almost surely, 2^204012509 is an apocalyptic number.

It is an amenable number.

204012509 is a deficient number, since it is larger than the sum of its proper divisors (1).

204012509 is an equidigital number, since it uses as much as digits as its factorization.

204012509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 204012509 is about 14283.2947529623. The cubic root of 204012509 is about 588.6885637214.

The spelling of 204012509 in words is "two hundred four million, twelve thousand, five hundred nine".