18391968489618 has 48 divisors (see below), whose sum is σ = 41553479787456. Its totient is φ = 6096785105520.

The previous prime is 18391968489607. The next prime is 18391968489701. The reversal of 18391968489618 is 81698486919381.

18391968489618 is a `hidden beast` number, since 1 + 8 + 3 + 9 + 19 + 68 + 489 + 61 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 104452246 + ... + 104628177.

It is an arithmetic number, because the mean of its divisors is an integer number (865697495572).

Almost surely, 2^{18391968489618} is an apocalyptic number.

18391968489618 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18391968489618 is an abundant number, since it is smaller than the sum of its proper divisors (23161511297838).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18391968489618 is a wasteful number, since it uses less digits than its factorization.

18391968489618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209080621 (or 209080609 counting only the distinct ones).

The product of its digits is 1289945088, while the sum is 81.

The spelling of 18391968489618 in words is "eighteen trillion, three hundred ninety-one billion, nine hundred sixty-eight million, four hundred eighty-nine thousand, six hundred eighteen".