18440181 has 12 divisors (see below), whose sum is σ = 27794208. Its totient is φ = 11758824.

The previous prime is 18440179. The next prime is 18440231. The reversal of 18440181 is 18104481.

18440181 is a `hidden beast` number, since 184 + 401 + 81 = 666.

It is not a de Polignac number, because 18440181 - 2¹ = 18440179 is a prime.

It is a super-3 number, since 3×18440181³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18440111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44335 + ... + 44748.

It is an arithmetic number, because the mean of its divisors is an integer number (2316184).

Almost surely, 2^18440181 is an apocalyptic number.

It is an amenable number.

18440181 is a deficient number, since it is larger than the sum of its proper divisors (9354027).

18440181 is a wasteful number, since it uses less digits than its factorization.

18440181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89112 (or 89109 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 27.

The square root of 18440181 is about 4294.2031856911. The cubic root of 18440181 is about 264.1932555355.

The spelling of 18440181 in words is "eighteen million, four hundred forty thousand, one hundred eighty-one".