18168352981 has 2 divisors, whose sum is σ = 18168352982. Its totient is φ = 18168352980.

The previous prime is 18168352967. The next prime is 18168353017. The reversal of 18168352981 is 18925386181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15898688100 + 2269664881 = 126090^2 + 47641^2 .

It is a cyclic number.

It is not a de Polignac number, because 18168352981 - 2⁹ = 18168352469 is a prime.

It is a super-2 number, since 2×18168352981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18168352921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9084176490 + 9084176491.

It is an arithmetic number, because the mean of its divisors is an integer number (9084176491).

Almost surely, 2^18168352981 is an apocalyptic number.

It is an amenable number.

18168352981 is a deficient number, since it is larger than the sum of its proper divisors (1).

18168352981 is an equidigital number, since it uses as much as digits as its factorization.

18168352981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 829440, while the sum is 52.

The spelling of 18168352981 in words is "eighteen billion, one hundred sixty-eight million, three hundred fifty-two thousand, nine hundred eighty-one".