856939 has 2 divisors, whose sum is σ = 856940. Its totient is φ = 856938.

The previous prime is 856927. The next prime is 856943. The reversal of 856939 is 939658.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 856939 - 2⁷ = 856811 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (856909) 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 as a sum of consecutive naturals, namely, 428469 + 428470.

It is an arithmetic number, because the mean of its divisors is an integer number (428470).

2⁸⁵⁶⁹³⁹ is an apocalyptic number.

856939 is a deficient number, since it is larger than the sum of its proper divisors (1).

856939 is an equidigital number, since it uses as much as digits as its factorization.

856939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58320, while the sum is 40.

The square root of 856939 is about 925.7099977855. The cubic root of 856939 is about 94.9838938531.

The spelling of 856939 in words is "eight hundred fifty-six thousand, nine hundred thirty-nine".