856663864 has 48 divisors (see below), whose sum is σ = 1978415280. Its totient is φ = 345542400.

The previous prime is 856663837. The next prime is 856663867. The reversal of 856663864 is 468366658.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856663867) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 57612 + ... + 70939.

It is an arithmetic number, because the mean of its divisors is an integer number (41216985).

Almost surely, 2^856663864 is an apocalyptic number.

It is an amenable number.

856663864 is an abundant number, since it is smaller than the sum of its proper divisors (1121751416).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

856663864 is a wasteful number, since it uses less digits than its factorization.

856663864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128588 (or 128577 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 52.

The square root of 856663864 is about 29268.8206800342. The cubic root of 856663864 is about 949.7372732395.

The spelling of 856663864 in words is "eight hundred fifty-six million, six hundred sixty-three thousand, eight hundred sixty-four".