865864 has 8 divisors (see below), whose sum is σ = 1623510. Its totient is φ = 432928.

The previous prime is 865859. The next prime is 865867. The reversal of 865864 is 468568.

It can be written as a sum of positive squares in only one way, i.e., 656100 + 209764 = 810^2 + 458^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is not an unprimeable number, because it can be changed into a prime (865867) by changing a digit.

865864 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54109 + ... + 54124.

2⁸⁶⁵⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

865864 is a deficient number, since it is larger than the sum of its proper divisors (757646).

865864 is a wasteful number, since it uses less digits than its factorization.

865864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108239 (or 108235 counting only the distinct ones).

The product of its digits is 46080, while the sum is 37.

The square root of 865864 is about 930.5181352343. The cubic root of 865864 is about 95.3125073367.

The spelling of 865864 in words is "eight hundred sixty-five thousand, eight hundred sixty-four".