856323161 has 4 divisors (see below), whose sum is σ = 856538292. Its totient is φ = 856108032.

The previous prime is 856323131. The next prime is 856323187. The reversal of 856323161 is 161323658.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 451307536 + 405015625 = 21244^2 + 20125^2 .

It is a cyclic number.

It is not a de Polignac number, because 856323161 - 2²⁶ = 789214297 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (856323121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101480 + ... + 109593.

It is an arithmetic number, because the mean of its divisors is an integer number (214134573).

Almost surely, 2^856323161 is an apocalyptic number.

It is an amenable number.

856323161 is a deficient number, since it is larger than the sum of its proper divisors (215131).

856323161 is a wasteful number, since it uses less digits than its factorization.

856323161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215130.

The product of its digits is 25920, while the sum is 35.

The square root of 856323161 is about 29262.9998633086. Note that the first 3 decimals coincide. The cubic root of 856323161 is about 949.6113501643.

The spelling of 856323161 in words is "eight hundred fifty-six million, three hundred twenty-three thousand, one hundred sixty-one".