18381138 has 16 divisors (see below), whose sum is σ = 36806400. Its totient is φ = 6119696.

The previous prime is 18381107. The next prime is 18381149. The reversal of 18381138 is 83118381.

It is a junction number, because it is equal to n+sod(n) for n = 18381099 and 18381108.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 6463 + ... + 8861.

It is an arithmetic number, because the mean of its divisors is an integer number (2300400).

Almost surely, 2^18381138 is an apocalyptic number.

18381138 is an abundant number, since it is smaller than the sum of its proper divisors (18425262).

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

18381138 is a wasteful number, since it uses less digits than its factorization.

18381138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3681.

The product of its digits is 4608, while the sum is 33.

The square root of 18381138 is about 4287.3229409504. The cubic root of 18381138 is about 263.9109835330.

The spelling of 18381138 in words is "eighteen million, three hundred eighty-one thousand, one hundred thirty-eight".