856308917 has 2 divisors, whose sum is σ = 856308918. Its totient is φ = 856308916.

The previous prime is 856308889. The next prime is 856308953. The reversal of 856308917 is 719803658.

It is a happy number.

856308917 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 827482756 + 28826161 = 28766^2 + 5369^2 .

It is a cyclic number.

It is not a de Polignac number, because 856308917 - 2¹⁸ = 856046773 is a prime.

It is a super-2 number, since 2×856308917² = 1466529922667425778, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856305917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428154458 + 428154459.

It is an arithmetic number, because the mean of its divisors is an integer number (428154459).

Almost surely, 2^856308917 is an apocalyptic number.

It is an amenable number.

856308917 is a deficient number, since it is larger than the sum of its proper divisors (1).

856308917 is an equidigital number, since it uses as much as digits as its factorization.

856308917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 47.

The square root of 856308917 is about 29262.7564832843. The cubic root of 856308917 is about 949.6060848861.

The spelling of 856308917 in words is "eight hundred fifty-six million, three hundred eight thousand, nine hundred seventeen".