856709 has 4 divisors (see below), whose sum is σ = 979104. Its totient is φ = 734316.

The previous prime is 856703. The next prime is 856711. The reversal of 856709 is 907658.

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 856709 - 2⁴ = 856693 is a prime.

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

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 856709.

It is not an unprimeable number, because it can be changed into a prime (856703) 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, 61187 + ... + 61200.

It is an arithmetic number, because the mean of its divisors is an integer number (244776).

2⁸⁵⁶⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

856709 is a deficient number, since it is larger than the sum of its proper divisors (122395).

856709 is a wasteful number, since it uses less digits than its factorization.

856709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122394.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 856709 is about 925.5857604782. The cubic root of 856709 is about 94.9753952901.

The spelling of 856709 in words is "eight hundred fifty-six thousand, seven hundred nine".