18126381 has 32 divisors (see below), whose sum is σ = 30220288. Its totient is φ = 9408960.

The previous prime is 18126341. The next prime is 18126389. The reversal of 18126381 is 18362181.

It is not a de Polignac number, because 18126381 - 2¹⁵ = 18093613 is a prime.

It is a super-2 number, since 2×18126381² = 657131376314322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18126389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17796 + ... + 18786.

It is an arithmetic number, because the mean of its divisors is an integer number (944384).

Almost surely, 2^18126381 is an apocalyptic number.

It is an amenable number.

18126381 is a deficient number, since it is larger than the sum of its proper divisors (12093907).

18126381 is a wasteful number, since it uses less digits than its factorization.

18126381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1081.

The product of its digits is 2304, while the sum is 30.

The square root of 18126381 is about 4257.5087786169. The cubic root of 18126381 is about 262.6860649080.

It can be divided in two parts, 181 and 26381, that added together give a palindrome (26562).

The spelling of 18126381 in words is "eighteen million, one hundred twenty-six thousand, three hundred eighty-one".