856889 has 4 divisors (see below), whose sum is σ = 934800. Its totient is φ = 778980.

The previous prime is 856853. The next prime is 856897. The reversal of 856889 is 988658.

856889 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 856889 - 2¹² = 852793 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (856789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38939 + ... + 38960.

It is an arithmetic number, because the mean of its divisors is an integer number (233700).

2⁸⁵⁶⁸⁸⁹ is an apocalyptic number.

It is an amenable number.

856889 is a deficient number, since it is larger than the sum of its proper divisors (77911).

856889 is a wasteful number, since it uses less digits than its factorization.

856889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77910.

The product of its digits is 138240, while the sum is 44.

The square root of 856889 is about 925.6829910936. The cubic root of 856889 is about 94.9820464688.

Subtracting 856889 from its reverse (988658), we obtain a square (131769 = 363²).

The spelling of 856889 in words is "eight hundred fifty-six thousand, eight hundred eighty-nine".