18916506960991 has 2 divisors, whose sum is σ = 18916506960992. Its totient is φ = 18916506960990.

The previous prime is 18916506960971. The next prime is 18916506961019. The reversal of 18916506960991 is 19906960561981.

It is a weak prime.

It is an emirp because it is prime and its reverse (19906960561981) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18916506960991 - 2¹⁷ = 18916506829919 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18916506960991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18916506960971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9458253480495 + 9458253480496.

It is an arithmetic number, because the mean of its divisors is an integer number (9458253480496).

Almost surely, 2^{18916506960991} is an apocalyptic number.

18916506960991 is a deficient number, since it is larger than the sum of its proper divisors (1).

18916506960991 is an equidigital number, since it uses as much as digits as its factorization.

18916506960991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56687040, while the sum is 70.

The spelling of 18916506960991 in words is "eighteen trillion, nine hundred sixteen billion, five hundred six million, nine hundred sixty thousand, nine hundred ninety-one".