90000018 has 32 divisors (see below), whose sum is σ = 204261120. Its totient is φ = 29360880.

The previous prime is 89999999. The next prime is 90000049. The reversal of 90000018 is 81000009.

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 (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15193 + ... + 20268.

It is an arithmetic number, because the mean of its divisors is an integer number (6383160).

Almost surely, 2^90000018 is an apocalyptic number.

90000018 is an abundant number, since it is smaller than the sum of its proper divisors (114261102).

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

90000018 is a wasteful number, since it uses less digits than its factorization.

90000018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35519 (or 35513 counting only the distinct ones).

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

The square root of 90000018 is about 9486.8339291884. The cubic root of 90000018 is about 448.1405045317.

Subtracting from 90000018 its reverse (81000009), we obtain a palindrome (9000009).

It can be divided in two parts, 9000001 and 8, that added together give a palindrome (9000009).

The spelling of 90000018 in words is "ninety million, eighteen", and thus it is an aban number and an uban number.