509969209 has 2 divisors, whose sum is σ = 509969210. Its totient is φ = 509969208.

The previous prime is 509969123. The next prime is 509969219. The reversal of 509969209 is 902969905.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 398202025 + 111767184 = 19955^2 + 10572^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-509969209 is a prime.

It is not a weakly prime, because it can be changed into another prime (509969219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 254984604 + 254984605.

It is an arithmetic number, because the mean of its divisors is an integer number (254984605).

Almost surely, 2^509969209 is an apocalyptic number.

It is an amenable number.

509969209 is a deficient number, since it is larger than the sum of its proper divisors (1).

509969209 is an equidigital number, since it uses as much as digits as its factorization.

509969209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 393660, while the sum is 49.

The square root of 509969209 is about 22582.4978467839. The cubic root of 509969209 is about 798.9408948433.

The spelling of 509969209 in words is "five hundred nine million, nine hundred sixty-nine thousand, two hundred nine".