2851865856 has 162 divisors, whose sum is σ = 9565481562. Its totient is φ = 814786560.

The previous prime is 2851865833. The next prime is 2851865873. The reversal of 2851865856 is 6585681582.

2851865856 is a `hidden beast` number, since 2 + 8 + 51 + 8 + 6 + 585 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1937408256 + 914457600 = 44016^2 + 30240^2 .

It is a super-2 number, since 2×2851865856² = 16266277721237225472, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 100266 + ... + 125526.

Almost surely, 2^2851865856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2851865856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4782740781).

2851865856 is an abundant number, since it is smaller than the sum of its proper divisors (6713615706).

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

2851865856 is a wasteful number, since it uses less digits than its factorization.

2851865856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25297 (or 25273 counting only the distinct ones).

The product of its digits is 4608000, while the sum is 54.

The square root of 2851865856 is about 53402.8637434361. The cubic root of 2851865856 is about 1418.1092762608.

It can be divided in two parts, 2851865 and 856, that added together give a square (2852721 = 1689²).

The spelling of 2851865856 in words is "two billion, eight hundred fifty-one million, eight hundred sixty-five thousand, eight hundred fifty-six".