856778285 has 16 divisors (see below), whose sum is σ = 1123345152. Its totient is φ = 622142400.

The previous prime is 856778261. The next prime is 856778287. The reversal of 856778285 is 582877658.

It is not a de Polignac number, because 856778285 - 2¹⁰ = 856777261 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 856778285.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856778287) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24572 + ... + 48138.

It is an arithmetic number, because the mean of its divisors is an integer number (70209072).

Almost surely, 2^856778285 is an apocalyptic number.

It is an amenable number.

856778285 is a deficient number, since it is larger than the sum of its proper divisors (266566867).

856778285 is a wasteful number, since it uses less digits than its factorization.

856778285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24244.

The product of its digits is 7526400, while the sum is 56.

The square root of 856778285 is about 29270.7752715913. The cubic root of 856778285 is about 949.7795554987.

The spelling of 856778285 in words is "eight hundred fifty-six million, seven hundred seventy-eight thousand, two hundred eighty-five".