18189771912 has 128 divisors (see below), whose sum is σ = 54641664000. Its totient is φ = 5573422080.

The previous prime is 18189771839. The next prime is 18189772001. The reversal of 18189771912 is 21917798181.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 663289 + ... + 690167.

It is an arithmetic number, because the mean of its divisors is an integer number (426888000).

Almost surely, 2^18189771912 is an apocalyptic number.

18189771912 is a gapful number since it is divisible by the number (12) 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 18189771912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27320832000).

18189771912 is an abundant number, since it is smaller than the sum of its proper divisors (36451892088).

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

18189771912 is a wasteful number, since it uses less digits than its factorization.

18189771912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27148 (or 27138 counting only the distinct ones).

The product of its digits is 508032, while the sum is 54.

The spelling of 18189771912 in words is "eighteen billion, one hundred eighty-nine million, seven hundred seventy-one thousand, nine hundred twelve".