856325809 has 2 divisors, whose sum is σ = 856325810. Its totient is φ = 856325808.

The previous prime is 856325777. The next prime is 856325867. The reversal of 856325809 is 908523658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 590635809 + 265690000 = 24303^2 + 16300^2 .

It is a cyclic number.

It is not a de Polignac number, because 856325809 - 2⁵ = 856325777 is a prime.

It is not a weakly prime, because it can be changed into another prime (856325209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428162904 + 428162905.

It is an arithmetic number, because the mean of its divisors is an integer number (428162905).

Almost surely, 2^856325809 is an apocalyptic number.

It is an amenable number.

856325809 is a deficient number, since it is larger than the sum of its proper divisors (1).

856325809 is an equidigital number, since it uses as much as digits as its factorization.

856325809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 518400, while the sum is 46.

The square root of 856325809 is about 29263.0451081223. The cubic root of 856325809 is about 949.6123289880.

The spelling of 856325809 in words is "eight hundred fifty-six million, three hundred twenty-five thousand, eight hundred nine".