856385685 has 24 divisors (see below), whose sum is σ = 1485165240. Its totient is φ = 456504192.

The previous prime is 856385671. The next prime is 856385687. The reversal of 856385685 is 586583658.

It can be written as a sum of positive squares in 4 ways, for example, as 34187409 + 822198276 = 5847^2 + 28674^2 .

It is not a de Polignac number, because 856385685 - 2⁴ = 856385669 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856385687) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 116911 + ... + 124019.

It is an arithmetic number, because the mean of its divisors is an integer number (61881885).

Almost surely, 2^856385685 is an apocalyptic number.

It is an amenable number.

856385685 is a deficient number, since it is larger than the sum of its proper divisors (628779555).

856385685 is a wasteful number, since it uses less digits than its factorization.

856385685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9797 (or 9794 counting only the distinct ones).

The product of its digits is 6912000, while the sum is 54.

The square root of 856385685 is about 29264.0681553334. The cubic root of 856385685 is about 949.6344613984.

The spelling of 856385685 in words is "eight hundred fifty-six million, three hundred eighty-five thousand, six hundred eighty-five".