855864 has 24 divisors (see below), whose sum is σ = 2318160. Its totient is φ = 285264.

The previous prime is 855863. The next prime is 855887. The reversal of 855864 is 468558.

It is a happy number.

855864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (24).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (855863) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5872 + ... + 6015.

It is an arithmetic number, because the mean of its divisors is an integer number (96590).

2⁸⁵⁵⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

855864 is an abundant number, since it is smaller than the sum of its proper divisors (1462296).

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

855864 is a wasteful number, since it uses less digits than its factorization.

855864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11899 (or 11892 counting only the distinct ones).

The product of its digits is 38400, while the sum is 36.

The square root of 855864 is about 925.1291801689. The cubic root of 855864 is about 94.9441592425.

It can be divided in two parts, 855 and 864, that multiplied together give a triangular number (738720 = T₁₂₁₅).

The spelling of 855864 in words is "eight hundred fifty-five thousand, eight hundred sixty-four".