90018 has 16 divisors (see below), whose sum is σ = 200160. Its totient is φ = 29988.

The previous prime is 90017. The next prime is 90019. The reversal of 90018 is 81009.

It is an interprime number because it is at equal distance from previous prime (90017) and next prime (90019).

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

It is not an unprimeable number, because it can be changed into a prime (90011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 780 + ... + 887.

It is an arithmetic number, because the mean of its divisors is an integer number (12510).

2⁹⁰⁰¹⁸ is an apocalyptic number.

90018 is an abundant number, since it is smaller than the sum of its proper divisors (110142).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100080).

90018 is a wasteful number, since it uses less digits than its factorization.

90018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1678 (or 1672 counting only the distinct ones).

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

The square root of 90018 is about 300.0299985001. The cubic root of 90018 is about 44.8170348696.

Subtracting from 90018 its sum of digits (18), we obtain a square (90000 = 300²).

Subtracting from 90018 its reverse (81009), we obtain a palindrome (9009).

It can be divided in two parts, 9001 and 8, that added together give a palindrome (9009).

The spelling of 90018 in words is "ninety thousand, eighteen".