181321091112 has 128 divisors (see below), whose sum is σ = 549499991040. Its totient is φ = 48672783360.

The previous prime is 181321091111. The next prime is 181321091143. The reversal of 181321091112 is 211190123181.

It is a self number, because there is not a number n which added to its sum of digits gives 181321091112.

It is not an unprimeable number, because it can be changed into a prime (181321091111) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1575183 + ... + 1686369.

It is an arithmetic number, because the mean of its divisors is an integer number (4292968680).

Almost surely, 2^181321091112 is an apocalyptic number.

181321091112 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 181321091112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (274749995520).

181321091112 is an abundant number, since it is smaller than the sum of its proper divisors (368178899928).

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

181321091112 is a wasteful number, since it uses less digits than its factorization.

181321091112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111791 (or 111787 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 30.

The spelling of 181321091112 in words is "one hundred eighty-one billion, three hundred twenty-one million, ninety-one thousand, one hundred twelve".