865641 has 8 divisors (see below), whose sum is σ = 1319104. Its totient is φ = 494640.

The previous prime is 865639. The next prime is 865643. The reversal of 865641 is 146568.

It is an interprime number because it is at equal distance from previous prime (865639) and next prime (865643).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 865641 - 2¹ = 865639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 865599 and 865608.

It is not an unprimeable number, because it can be changed into a prime (865643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20590 + ... + 20631.

It is an arithmetic number, because the mean of its divisors is an integer number (164888).

2⁸⁶⁵⁶⁴¹ is an apocalyptic number.

It is an amenable number.

865641 is a deficient number, since it is larger than the sum of its proper divisors (453463).

865641 is a wasteful number, since it uses less digits than its factorization.

865641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41231.

The product of its digits is 5760, while the sum is 30.

The square root of 865641 is about 930.3983018041. The cubic root of 865641 is about 95.3043241755.

The spelling of 865641 in words is "eight hundred sixty-five thousand, six hundred forty-one".