856705 has 4 divisors (see below), whose sum is σ = 1028052. Its totient is φ = 685360.

The previous prime is 856703. The next prime is 856711. The reversal of 856705 is 507658.

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

It can be written as a sum of positive squares in 2 ways, for example, as 229441 + 627264 = 479^2 + 792^2 .

It is not a de Polignac number, because 856705 - 2¹ = 856703 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

856705 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85666 + ... + 85675.

It is an arithmetic number, because the mean of its divisors is an integer number (257013).

2⁸⁵⁶⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

856705 is a deficient number, since it is larger than the sum of its proper divisors (171347).

856705 is a wasteful number, since it uses less digits than its factorization.

856705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171346.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 856705 is about 925.5835996818. The cubic root of 856705 is about 94.9752474755.

The spelling of 856705 in words is "eight hundred fifty-six thousand, seven hundred five".