18324181 has 4 divisors (see below), whose sum is σ = 19402092. Its totient is φ = 17246272.

The previous prime is 18324179. The next prime is 18324191. The reversal of 18324181 is 18142381.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12895281 + 5428900 = 3591^2 + 2330^2 .

It is a cyclic number.

It is not a de Polignac number, because 18324181 - 2¹ = 18324179 is a prime.

It is a super-2 number, since 2×18324181² = 671551218641522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18324101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 538930 + ... + 538963.

It is an arithmetic number, because the mean of its divisors is an integer number (4850523).

Almost surely, 2^18324181 is an apocalyptic number.

It is an amenable number.

18324181 is a deficient number, since it is larger than the sum of its proper divisors (1077911).

18324181 is a wasteful number, since it uses less digits than its factorization.

18324181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1077910.

The product of its digits is 1536, while the sum is 28.

The square root of 18324181 is about 4280.6752971932. The cubic root of 18324181 is about 263.6381108629.

The spelling of 18324181 in words is "eighteen million, three hundred twenty-four thousand, one hundred eighty-one".