165823181 has 2 divisors, whose sum is σ = 165823182. Its totient is φ = 165823180.

The previous prime is 165823171. The next prime is 165823199. The reversal of 165823181 is 181328561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145202500 + 20620681 = 12050^2 + 4541^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165823181 is a prime.

It is a super-2 number, since 2×165823181² = 54994654713917522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165823171) 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, 82911590 + 82911591.

It is an arithmetic number, because the mean of its divisors is an integer number (82911591).

Almost surely, 2^165823181 is an apocalyptic number.

It is an amenable number.

165823181 is a deficient number, since it is larger than the sum of its proper divisors (1).

165823181 is an equidigital number, since it uses as much as digits as its factorization.

165823181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 35.

The square root of 165823181 is about 12877.2349904784. The cubic root of 165823181 is about 549.3912614846.

The spelling of 165823181 in words is "one hundred sixty-five million, eight hundred twenty-three thousand, one hundred eighty-one".