18116388 has 18 divisors (see below), whose sum is σ = 45794294. Its totient is φ = 6038784.

The previous prime is 18116353. The next prime is 18116393. The reversal of 18116388 is 88361181.

18116388 is a `hidden beast` number, since 1 + 8 + 11 + 638 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 17489124 + 627264 = 4182^2 + 792^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 503233 = 18116388 / (1 + 8 + 1 + 1 + 6 + 3 + 8 + 8).

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 5 ways as a sum of consecutive naturals, for example, 251581 + ... + 251652.

Almost surely, 2^18116388 is an apocalyptic number.

18116388 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18116388 is an abundant number, since it is smaller than the sum of its proper divisors (27677906).

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

18116388 is a wasteful number, since it uses less digits than its factorization.

18116388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503243 (or 503238 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 18116388 is about 4256.3350432032. The cubic root of 18116388 is about 262.6377834486.

The spelling of 18116388 in words is "eighteen million, one hundred sixteen thousand, three hundred eighty-eight".