816162181 has 2 divisors, whose sum is σ = 816162182. Its totient is φ = 816162180.

The previous prime is 816162173. The next prime is 816162187. The reversal of 816162181 is 181261618.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 729486081 + 86676100 = 27009^2 + 9310^2 .

It is a cyclic number.

It is not a de Polignac number, because 816162181 - 2³ = 816162173 is a prime.

It is a super-2 number, since 2×816162181² = 1332241411389353522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (816162187) 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, 408081090 + 408081091.

It is an arithmetic number, because the mean of its divisors is an integer number (408081091).

Almost surely, 2^816162181 is an apocalyptic number.

It is an amenable number.

816162181 is a deficient number, since it is larger than the sum of its proper divisors (1).

816162181 is an equidigital number, since it uses as much as digits as its factorization.

816162181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4608, while the sum is 34.

The square root of 816162181 is about 28568.5523084387. The cubic root of 816162181 is about 934.5276503074.

The spelling of 816162181 in words is "eight hundred sixteen million, one hundred sixty-two thousand, one hundred eighty-one".