856745161 has 2 divisors, whose sum is σ = 856745162. Its totient is φ = 856745160.

The previous prime is 856745137. The next prime is 856745177. The reversal of 856745161 is 161547658.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 842160400 + 14584761 = 29020^2 + 3819^2 .

It is a cyclic number.

It is not a de Polignac number, because 856745161 - 2⁵ = 856745129 is a prime.

It is not a weakly prime, because it can be changed into another prime (856745111) 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, 428372580 + 428372581.

It is an arithmetic number, because the mean of its divisors is an integer number (428372581).

Almost surely, 2^856745161 is an apocalyptic number.

It is an amenable number.

856745161 is a deficient number, since it is larger than the sum of its proper divisors (1).

856745161 is an equidigital number, since it uses as much as digits as its factorization.

856745161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 201600, while the sum is 43.

The square root of 856745161 is about 29270.2094457829. The cubic root of 856745161 is about 949.7673154968.

The spelling of 856745161 in words is "eight hundred fifty-six million, seven hundred forty-five thousand, one hundred sixty-one".