856439 has 8 divisors (see below), whose sum is σ = 893760. Its totient is φ = 819936.

The previous prime is 856421. The next prime is 856441. The reversal of 856439 is 934658.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856439 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 856399 and 856408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856459) 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 7 ways as a sum of consecutive naturals, for example, 2777 + ... + 3069.

It is an arithmetic number, because the mean of its divisors is an integer number (111720).

2⁸⁵⁶⁴³⁹ is an apocalyptic number.

856439 is a deficient number, since it is larger than the sum of its proper divisors (37321).

856439 is a wasteful number, since it uses less digits than its factorization.

856439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409.

The product of its digits is 25920, while the sum is 35.

The square root of 856439 is about 925.4398954011. The cubic root of 856439 is about 94.9654167749.

The spelling of 856439 in words is "eight hundred fifty-six thousand, four hundred thirty-nine".