856478778 has 32 divisors (see below), whose sum is σ = 1744209600. Its totient is φ = 280319616.

The previous prime is 856478767. The next prime is 856478783. The reversal of 856478778 is 877874658.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 96033 + ... + 104571.

It is an arithmetic number, because the mean of its divisors is an integer number (54506550).

Almost surely, 2^856478778 is an apocalyptic number.

856478778 is an abundant number, since it is smaller than the sum of its proper divisors (887730822).

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

856478778 is a wasteful number, since it uses less digits than its factorization.

856478778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8846.

The product of its digits is 21073920, while the sum is 60.

The square root of 856478778 is about 29265.6586804398. The cubic root of 856478778 is about 949.6688700063.

The spelling of 856478778 in words is "eight hundred fifty-six million, four hundred seventy-eight thousand, seven hundred seventy-eight".