12985809 has 4 divisors (see below), whose sum is σ = 17314416. Its totient is φ = 8657204.

The previous prime is 12985801. The next prime is 12985867. The reversal of 12985809 is 90858921.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12985809 - 2³ = 12985801 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12985801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2164299 + ... + 2164304.

It is an arithmetic number, because the mean of its divisors is an integer number (4328604).

Almost surely, 2^12985809 is an apocalyptic number.

It is an amenable number.

12985809 is a deficient number, since it is larger than the sum of its proper divisors (4328607).

12985809 is an equidigital number, since it uses as much as digits as its factorization.

12985809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4328606.

The product of its (nonzero) digits is 51840, while the sum is 42.

The square root of 12985809 is about 3603.5828004918. The cubic root of 12985809 is about 235.0478791836.

The spelling of 12985809 in words is "twelve million, nine hundred eighty-five thousand, eight hundred nine".