856859873 has 2 divisors, whose sum is σ = 856859874. Its totient is φ = 856859872.

The previous prime is 856859869. The next prime is 856859881. The reversal of 856859873 is 378958658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 537451489 + 319408384 = 23183^2 + 17872^2 .

It is a cyclic number.

It is not a de Polignac number, because 856859873 - 2² = 856859869 is a prime.

It is a super-2 number, since 2×856859873² = 1468417683915152258, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (856859893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428429936 + 428429937.

It is an arithmetic number, because the mean of its divisors is an integer number (428429937).

Almost surely, 2^856859873 is an apocalyptic number.

It is an amenable number.

856859873 is a deficient number, since it is larger than the sum of its proper divisors (1).

856859873 is an equidigital number, since it uses as much as digits as its factorization.

856859873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14515200, while the sum is 59.

The square root of 856859873 is about 29272.1689152000. The cubic root of 856859873 is about 949.8097026037.

The spelling of 856859873 in words is "eight hundred fifty-six million, eight hundred fifty-nine thousand, eight hundred seventy-three".