865128 has 64 divisors (see below), whose sum is σ = 2462400. Its totient is φ = 250880.

The previous prime is 865121. The next prime is 865153. The reversal of 865128 is 821568.

865128 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 865095 and 865104.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 865128.

It is not an unprimeable number, because it can be changed into a prime (865121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7600 + ... + 7712.

It is an arithmetic number, because the mean of its divisors is an integer number (38475).

2⁸⁶⁵¹²⁸ is an apocalyptic number.

865128 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 865128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1231200).

865128 is an abundant number, since it is smaller than the sum of its proper divisors (1597272).

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

865128 is a wasteful number, since it uses less digits than its factorization.

865128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 158 counting only the distinct ones).

The product of its digits is 3840, while the sum is 30.

The square root of 865128 is about 930.1225725677. The cubic root of 865128 is about 95.2854938985.

The spelling of 865128 in words is "eight hundred sixty-five thousand, one hundred twenty-eight".