861816858184 has 16 divisors (see below), whose sum is σ = 1671627527100. Its totient is φ = 416049517632.

The previous prime is 861816858169. The next prime is 861816858193. The reversal of 861816858184 is 481858618168.

It can be written as a sum of positive squares in 2 ways, for example, as 855976536100 + 5840322084 = 925190^2 + 76422^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1857363687 + ... + 1857364150.

Almost surely, 2^861816858184 is an apocalyptic number.

It is an amenable number.

861816858184 is a deficient number, since it is larger than the sum of its proper divisors (809810668916).

861816858184 is a wasteful number, since it uses less digits than its factorization.

861816858184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3714727872 (or 3714727868 counting only the distinct ones).

The product of its digits is 23592960, while the sum is 64.

The spelling of 861816858184 in words is "eight hundred sixty-one billion, eight hundred sixteen million, eight hundred fifty-eight thousand, one hundred eighty-four".