865985013 has 20 divisors (see below), whose sum is σ = 1301398560. Its totient is φ = 573857352.

The previous prime is 865984997. The next prime is 865985027. The reversal of 865985013 is 310589568.

865985013 is a `hidden beast` number, since 8 + 6 + 598 + 50 + 1 + 3 = 666.

It is not a de Polignac number, because 865985013 - 2⁴ = 865984997 is a prime.

It is a super-2 number, since 2×865985013² = 1499860085481220338, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 865985013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865965013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 18483 + ... + 45536.

It is an arithmetic number, because the mean of its divisors is an integer number (65069928).

Almost surely, 2^865985013 is an apocalyptic number.

It is an amenable number.

865985013 is a deficient number, since it is larger than the sum of its proper divisors (435413547).

865985013 is a wasteful number, since it uses less digits than its factorization.

865985013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64198 (or 64189 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The square root of 865985013 is about 29427.6232985268. The cubic root of 865985013 is about 953.1694741630.

The spelling of 865985013 in words is "eight hundred sixty-five million, nine hundred eighty-five thousand, thirteen".