18123099920 has 80 divisors (see below), whose sum is σ = 44603127360. Its totient is φ = 6836454912.

The previous prime is 18123099913. The next prime is 18123099961. The reversal of 18123099920 is 2999032181.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8927 + ... + 190593.

It is an arithmetic number, because the mean of its divisors is an integer number (557539092).

Almost surely, 2^18123099920 is an apocalyptic number.

18123099920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18123099920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22301563680).

18123099920 is an abundant number, since it is smaller than the sum of its proper divisors (26480027440).

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

18123099920 is a wasteful number, since it uses less digits than its factorization.

18123099920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181752 (or 181746 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 44.

The spelling of 18123099920 in words is "eighteen billion, one hundred twenty-three million, ninety-nine thousand, nine hundred twenty".