18005688 has 96 divisors (see below), whose sum is σ = 51891840. Its totient is φ = 5628480.

The previous prime is 18005681. The next prime is 18005707. The reversal of 18005688 is 88650081.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18005681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 137383 + ... + 137513.

It is an arithmetic number, because the mean of its divisors is an integer number (540540).

Almost surely, 2^18005688 is an apocalyptic number.

18005688 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18005688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25945920).

18005688 is an abundant number, since it is smaller than the sum of its proper divisors (33886152).

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

18005688 is a wasteful number, since it uses less digits than its factorization.

18005688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249 (or 242 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 18005688 is about 4243.3109713996. The cubic root of 18005688 is about 262.1017416563.

The spelling of 18005688 in words is "eighteen million, five thousand, six hundred eighty-eight".