18885016871989 has 2 divisors, whose sum is σ = 18885016871990. Its totient is φ = 18885016871988.

The previous prime is 18885016871971. The next prime is 18885016872023. The reversal of 18885016871989 is 98917861058881.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15666096473764 + 3218920398225 = 3958042^2 + 1794135^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18885016871989 is a prime.

It is a super-2 number, since 2×18885016871989² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18885016871089) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9442508435994 + 9442508435995.

It is an arithmetic number, because the mean of its divisors is an integer number (9442508435995).

Almost surely, 2^{18885016871989} is an apocalyptic number.

It is an amenable number.

18885016871989 is a deficient number, since it is larger than the sum of its proper divisors (1).

18885016871989 is an equidigital number, since it uses as much as digits as its factorization.

18885016871989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 557383680, while the sum is 79.

The spelling of 18885016871989 in words is "eighteen trillion, eight hundred eighty-five billion, sixteen million, eight hundred seventy-one thousand, nine hundred eighty-nine".