865855 has 8 divisors (see below), whose sum is σ = 1046592. Its totient is φ = 687648.

The previous prime is 865847. The next prime is 865859. The reversal of 865855 is 558568.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 865855 - 2³ = 865847 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865859) 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 7 ways as a sum of consecutive naturals, for example, 234 + ... + 1336.

It is an arithmetic number, because the mean of its divisors is an integer number (130824).

2⁸⁶⁵⁸⁵⁵ is an apocalyptic number.

865855 is a deficient number, since it is larger than the sum of its proper divisors (180737).

865855 is a wasteful number, since it uses less digits than its factorization.

865855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1265.

The product of its digits is 48000, while the sum is 37.

The square root of 865855 is about 930.5132992064. The cubic root of 865855 is about 95.3121771018.

The spelling of 865855 in words is "eight hundred sixty-five thousand, eight hundred fifty-five".