12811509 has 24 divisors (see below), whose sum is σ = 19285760. Its totient is φ = 8188128.

The previous prime is 12811499. The next prime is 12811511. The reversal of 12811509 is 90511821.

It is not a de Polignac number, because 12811509 - 2⁴ = 12811493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12811559) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26064 + ... + 26550.

Almost surely, 2^12811509 is an apocalyptic number.

It is an amenable number.

12811509 is a deficient number, since it is larger than the sum of its proper divisors (6474251).

12811509 is a wasteful number, since it uses less digits than its factorization.

12811509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609 (or 606 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 12811509 is about 3579.3168342576. The cubic root of 12811509 is about 233.9915074718.

The spelling of 12811509 in words is "twelve million, eight hundred eleven thousand, five hundred nine".