861287985 has 28 divisors (see below), whose sum is σ = 1549616052. Its totient is φ = 459351648.

The previous prime is 861287953. The next prime is 861288013. The reversal of 861287985 is 589782168.

861287985 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 591802929 + 269485056 = 24327^2 + 16416^2 .

It is not a de Polignac number, because 861287985 - 2⁵ = 861287953 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 114502 + ... + 121791.

Almost surely, 2^861287985 is an apocalyptic number.

It is an amenable number.

861287985 is a deficient number, since it is larger than the sum of its proper divisors (688328067).

861287985 is an equidigital number, since it uses as much as digits as its factorization.

861287985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236316 (or 236301 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 54.

The square root of 861287985 is about 29347.7083432421. The cubic root of 861287985 is about 951.4430460597.

The spelling of 861287985 in words is "eight hundred sixty-one million, two hundred eighty-seven thousand, nine hundred eighty-five".