181998180 has 288 divisors, whose sum is σ = 698600448. Its totient is φ = 37324800.

The previous prime is 181998161. The next prime is 181998181. The reversal of 181998180 is 81899181.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (181998181) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 671445 + ... + 671715.

It is an arithmetic number, because the mean of its divisors is an integer number (2425696).

Almost surely, 2^181998180 is an apocalyptic number.

181998180 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 181998180, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349300224).

181998180 is an abundant number, since it is smaller than the sum of its proper divisors (516602268).

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

181998180 is a wasteful number, since it uses less digits than its factorization.

181998180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347 (or 342 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 45.

The square root of 181998180 is about 13490.6701093756. The cubic root of 181998180 is about 566.7032217864.

181998180 divided by its sum of digits (45) gives a palindrome (4044404).

It can be divided in two parts, 1819 and 98180, that added together give a palindrome (99999).

The spelling of 181998180 in words is "one hundred eighty-one million, nine hundred ninety-eight thousand, one hundred eighty".