856862609 has 2 divisors, whose sum is σ = 856862610. Its totient is φ = 856862608.

The previous prime is 856862597. The next prime is 856862639. The reversal of 856862609 is 906268658.

856862609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 841870225 + 14992384 = 29015^2 + 3872^2 .

It is a cyclic number.

It is not a de Polignac number, because 856862609 - 2²⁸ = 588427153 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (856862639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428431304 + 428431305.

It is an arithmetic number, because the mean of its divisors is an integer number (428431305).

Almost surely, 2^856862609 is an apocalyptic number.

It is an amenable number.

856862609 is a deficient number, since it is larger than the sum of its proper divisors (1).

856862609 is an equidigital number, since it uses as much as digits as its factorization.

856862609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1244160, while the sum is 50.

The square root of 856862609 is about 29272.2156489733. The cubic root of 856862609 is about 949.8107135339.

The spelling of 856862609 in words is "eight hundred fifty-six million, eight hundred sixty-two thousand, six hundred nine".