12736809 has 12 divisors (see below), whose sum is σ = 18434052. Its totient is φ = 8474400.

The previous prime is 12736799. The next prime is 12736811. The reversal of 12736809 is 90863721.

It can be written as a sum of positive squares in 2 ways, for example, as 11289600 + 1447209 = 3360^2 + 1203^2 .

It is not a de Polignac number, because 12736809 - 2⁴ = 12736793 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12736819) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4879 + ... + 7019.

It is an arithmetic number, because the mean of its divisors is an integer number (1536171).

Almost surely, 2^12736809 is an apocalyptic number.

It is an amenable number.

12736809 is a deficient number, since it is larger than the sum of its proper divisors (5697243).

12736809 is a wasteful number, since it uses less digits than its factorization.

12736809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2808 (or 2805 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 12736809 is about 3568.8666268159. The cubic root of 12736809 is about 233.5358430121.

The spelling of 12736809 in words is "twelve million, seven hundred thirty-six thousand, eight hundred nine".