856671 has 4 divisors (see below), whose sum is σ = 1142232. Its totient is φ = 571112.

The previous prime is 856649. The next prime is 856693. The reversal of 856671 is 176658.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (856649) and next prime (856693).

It is a cyclic number.

It is not a de Polignac number, because 856671 - 2¹⁵ = 823903 is a prime.

It is a D-number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 856671.

It is not an unprimeable number, because it can be changed into a prime (856571) 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 3 ways as a sum of consecutive naturals, for example, 142776 + ... + 142781.

It is an arithmetic number, because the mean of its divisors is an integer number (285558).

2⁸⁵⁶⁶⁷¹ is an apocalyptic number.

856671 is a deficient number, since it is larger than the sum of its proper divisors (285561).

856671 is a wasteful number, since it uses less digits than its factorization.

856671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285560.

The product of its digits is 10080, while the sum is 33.

The square root of 856671 is about 925.5652327092. The cubic root of 856671 is about 94.9739910332.

The spelling of 856671 in words is "eight hundred fifty-six thousand, six hundred seventy-one".