12805809 has 4 divisors (see below), whose sum is σ = 17074416. Its totient is φ = 8537204.

The previous prime is 12805799. The next prime is 12805813. The reversal of 12805809 is 90850821.

It is a happy number.

12805809 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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 12805809 - 2¹⁵ = 12773041 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12805809.

It is not an unprimeable number, because it can be changed into a prime (12805609) 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, 2134299 + ... + 2134304.

It is an arithmetic number, because the mean of its divisors is an integer number (4268604).

Almost surely, 2^12805809 is an apocalyptic number.

It is an amenable number.

12805809 is a deficient number, since it is larger than the sum of its proper divisors (4268607).

12805809 is an equidigital number, since it uses as much as digits as its factorization.

12805809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4268606.

The product of its (nonzero) digits is 5760, while the sum is 33.

The square root of 12805809 is about 3578.5205043425. The cubic root of 12805809 is about 233.9568004116.

The spelling of 12805809 in words is "twelve million, eight hundred five thousand, eight hundred nine".