856999 has 12 divisors (see below), whose sum is σ = 1014552. Its totient is φ = 717600.

The previous prime is 856993. The next prime is 857009. The reversal of 856999 is 999658.

It is a happy number.

It is not a de Polignac number, because 856999 - 2⁹ = 856487 is a prime.

856999 is a modest number, since divided by 999 gives 856 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856993) 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 11 ways as a sum of consecutive naturals, for example, 1629 + ... + 2089.

It is an arithmetic number, because the mean of its divisors is an integer number (84546).

2⁸⁵⁶⁹⁹⁹ is an apocalyptic number.

856999 is a deficient number, since it is larger than the sum of its proper divisors (157553).

856999 is a wasteful number, since it uses less digits than its factorization.

856999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498 (or 485 counting only the distinct ones).

The product of its digits is 174960, while the sum is 46.

The square root of 856999 is about 925.7424047758. The cubic root of 856999 is about 94.9861106195.

It can be divided in two parts, 8569 and 99, that added together give a palindrome (8668).

The spelling of 856999 in words is "eight hundred fifty-six thousand, nine hundred ninety-nine".