18000090 has 64 divisors (see below), whose sum is σ = 48412800. Its totient is φ = 4758912.

The previous prime is 18000089. The next prime is 18000137. The reversal of 18000090 is 9000081.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 31 ways as a sum of consecutive naturals, for example, 43806 + ... + 44214.

It is an arithmetic number, because the mean of its divisors is an integer number (756450).

Almost surely, 2^18000090 is an apocalyptic number.

18000090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18000090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24206400).

18000090 is an abundant number, since it is smaller than the sum of its proper divisors (30412710).

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

18000090 is a wasteful number, since it uses less digits than its factorization.

18000090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 588 (or 582 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 18000090 is about 4242.6512937077. The cubic root of 18000090 is about 262.0745762104.

Subtracting from 18000090 its reverse (9000081), we obtain a palindrome (9000009).

The spelling of 18000090 in words is "eighteen million, ninety", and thus it is an aban number and an uban number.