865085880 has 64 divisors (see below), whose sum is σ = 2609661600. Its totient is φ = 229409280.

The previous prime is 865085873. The next prime is 865085887. The reversal of 865085880 is 88580568.

It is an interprime number because it is at equal distance from previous prime (865085873) and next prime (865085887).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865085887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1806 + ... + 41634.

Almost surely, 2^865085880 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 865085880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1304830800).

865085880 is an abundant number, since it is smaller than the sum of its proper divisors (1744575720).

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

865085880 is a wasteful number, since it uses less digits than its factorization.

865085880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40024 (or 40020 counting only the distinct ones).

The product of its (nonzero) digits is 614400, while the sum is 48.

The square root of 865085880 is about 29412.3423072696. The cubic root of 865085880 is about 952.8394750300.

The spelling of 865085880 in words is "eight hundred sixty-five million, eighty-five thousand, eight hundred eighty".