181989120 has 144 divisors (see below), whose sum is σ = 589260672. Its totient is φ = 47861760.

The previous prime is 181989113. The next prime is 181989139. The reversal of 181989120 is 21989181.

It is a congruent number.

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, 318435 + ... + 319005.

It is an arithmetic number, because the mean of its divisors is an integer number (4092088).

Almost surely, 2^181989120 is an apocalyptic number.

181989120 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 181989120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294630336).

181989120 is an abundant number, since it is smaller than the sum of its proper divisors (407271552).

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

181989120 is an equidigital number, since it uses as much as digits as its factorization.

181989120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 678 (or 664 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 39.

The square root of 181989120 is about 13490.3343175772. The cubic root of 181989120 is about 566.6938179993.

The spelling of 181989120 in words is "one hundred eighty-one million, nine hundred eighty-nine thousand, one hundred twenty".