12855809 has 2 divisors, whose sum is σ = 12855810. Its totient is φ = 12855808.

The previous prime is 12855797. The next prime is 12855823. The reversal of 12855809 is 90855821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12054784 + 801025 = 3472^2 + 895^2 .

It is a cyclic number.

It is not a de Polignac number, because 12855809 - 2²⁰ = 11807233 is a prime.

It is not a weakly prime, because it can be changed into another prime (12855889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6427904 + 6427905.

It is an arithmetic number, because the mean of its divisors is an integer number (6427905).

Almost surely, 2^12855809 is an apocalyptic number.

It is an amenable number.

12855809 is a deficient number, since it is larger than the sum of its proper divisors (1).

12855809 is an equidigital number, since it uses as much as digits as its factorization.

12855809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28800, while the sum is 38.

The square root of 12855809 is about 3585.4998256868. The cubic root of 12855809 is about 234.2608980365.

The spelling of 12855809 in words is "twelve million, eight hundred fifty-five thousand, eight hundred nine".