18989844618 has 16 divisors (see below), whose sum is σ = 38371233600. Its totient is φ = 6264690816.

The previous prime is 18989844613. The next prime is 18989844631. The reversal of 18989844618 is 81644898981.

It is a super-2 number, since 2×18989844618² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18989844613) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16313718 + ... + 16314881.

It is an arithmetic number, because the mean of its divisors is an integer number (2398202100).

Almost surely, 2^18989844618 is an apocalyptic number.

18989844618 is an abundant number, since it is smaller than the sum of its proper divisors (19381388982).

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

18989844618 is a wasteful number, since it uses less digits than its factorization.

18989844618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32628701.

The product of its digits is 31850496, while the sum is 66.

The spelling of 18989844618 in words is "eighteen billion, nine hundred eighty-nine million, eight hundred forty-four thousand, six hundred eighteen".