18887681231999 has 2 divisors, whose sum is σ = 18887681232000. Its totient is φ = 18887681231998.

The previous prime is 18887681231989. The next prime is 18887681232029. The reversal of 18887681231999 is 99913218678881.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18887681231999 - 2¹² = 18887681227903 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18887681231989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9443840615999 + 9443840616000.

It is an arithmetic number, because the mean of its divisors is an integer number (9443840616000).

Almost surely, 2^{18887681231999} is an apocalyptic number.

18887681231999 is a deficient number, since it is larger than the sum of its proper divisors (1).

18887681231999 is an equidigital number, since it uses as much as digits as its factorization.

18887681231999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 752467968, while the sum is 80.

The spelling of 18887681231999 in words is "eighteen trillion, eight hundred eighty-seven billion, six hundred eighty-one million, two hundred thirty-one thousand, nine hundred ninety-nine".