18122181 has 32 divisors (see below), whose sum is σ = 31718400. Its totient is φ = 8916480.

The previous prime is 18122179. The next prime is 18122191.

18122181 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18122181 - 2¹ = 18122179 is a prime.

It is a super-2 number, since 2×18122181² = 656826888393522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18122101) 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, 2325 + ... + 6453.

It is an arithmetic number, because the mean of its divisors is an integer number (991200).

Almost surely, 2^18122181 is an apocalyptic number.

18122181 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18122181 is a deficient number, since it is larger than the sum of its proper divisors (13596219).

18122181 is a wasteful number, since it uses less digits than its factorization.

18122181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4169.

The product of its digits is 256, while the sum is 24.

The square root of 18122181 is about 4257.0155038477. The cubic root of 18122181 is about 262.6657746526.

It can be divided in two parts, 1812 and 2181, that added together give a palindrome (3993).

The spelling of 18122181 in words is "eighteen million, one hundred twenty-two thousand, one hundred eighty-one".