998817718867 has 2 divisors, whose sum is σ = 998817718868. Its totient is φ = 998817718866.

The previous prime is 998817718853. The next prime is 998817718909. The reversal of 998817718867 is 768817718899.

It is a weak prime.

It is an emirp because it is prime and its reverse (768817718899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 998817718867 - 2²⁷ = 998683501139 is a prime.

It is not a weakly prime, because it can be changed into another prime (998817718817) 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, 499408859433 + 499408859434.

It is an arithmetic number, because the mean of its divisors is an integer number (499408859434).

Almost surely, 2^998817718867 is an apocalyptic number.

998817718867 is a deficient number, since it is larger than the sum of its proper divisors (1).

998817718867 is an equidigital number, since it uses as much as digits as its factorization.

998817718867 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 682795008, while the sum is 79.

The spelling of 998817718867 in words is "nine hundred ninety-eight billion, eight hundred seventeen million, seven hundred eighteen thousand, eight hundred sixty-seven".