18168686181 has 24 divisors (see below), whose sum is σ = 27812897280. Its totient is φ = 11721716280.

The previous prime is 18168686153. The next prime is 18168686197.

It is a happy number.

18168686181 is a `hidden beast` number, since 1 + 8 + 16 + 8 + 6 + 8 + 618 + 1 = 666.

18168686181 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18168686181 - 2⁹ = 18168685669 is a prime.

It is a super-2 number, since 2×18168686181² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18168686281) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 324165 + ... + 376058.

It is an arithmetic number, because the mean of its divisors is an integer number (1158870720).

Almost surely, 2^18168686181 is an apocalyptic number.

It is an amenable number.

18168686181 is a deficient number, since it is larger than the sum of its proper divisors (9644211099).

18168686181 is an equidigital number, since it uses as much as digits as its factorization.

18168686181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700294 (or 700257 counting only the distinct ones).

The product of its digits is 884736, while the sum is 54.

The spelling of 18168686181 in words is "eighteen billion, one hundred sixty-eight million, six hundred eighty-six thousand, one hundred eighty-one".