856139 has 2 divisors, whose sum is σ = 856140. Its totient is φ = 856138.

The previous prime is 856133. The next prime is 856147. The reversal of 856139 is 931658.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856139 is a prime.

It is not a weakly prime, because it can be changed into another prime (856133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428069 + 428070.

It is an arithmetic number, because the mean of its divisors is an integer number (428070).

2⁸⁵⁶¹³⁹ is an apocalyptic number.

856139 is a deficient number, since it is larger than the sum of its proper divisors (1).

856139 is an equidigital number, since it uses as much as digits as its factorization.

856139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 32.

The square root of 856139 is about 925.2777961240. The cubic root of 856139 is about 94.9543270759.

The spelling of 856139 in words is "eight hundred fifty-six thousand, one hundred thirty-nine".