509009 has 4 divisors (see below), whose sum is σ = 522804. Its totient is φ = 495216.

The previous prime is 508987. The next prime is 509023. The reversal of 509009 is 900905.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 900905 = 5 ⋅180181.

It can be written as a sum of positive squares in 2 ways, for example, as 222784 + 286225 = 472^2 + 535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-509009 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (509909) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6842 + ... + 6915.

It is an arithmetic number, because the mean of its divisors is an integer number (130701).

2⁵⁰⁹⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

509009 is a deficient number, since it is larger than the sum of its proper divisors (13795).

509009 is a wasteful number, since it uses less digits than its factorization.

509009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13794.

The product of its (nonzero) digits is 405, while the sum is 23.

The square root of 509009 is about 713.4486666888. The cubic root of 509009 is about 79.8439144142.

The spelling of 509009 in words is "five hundred nine thousand, nine".