18085998 has 48 divisors (see below), whose sum is σ = 42418944. Its totient is φ = 5125680.

The previous prime is 18085997. The next prime is 18086009. The reversal of 18085998 is 89958081.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18085993) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 66603 + ... + 66873.

It is an arithmetic number, because the mean of its divisors is an integer number (883728).

Almost surely, 2^18085998 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18085998, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21209472).

18085998 is an abundant number, since it is smaller than the sum of its proper divisors (24332946).

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

18085998 is a wasteful number, since it uses less digits than its factorization.

18085998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 48.

The square root of 18085998 is about 4252.7635720787. The cubic root of 18085998 is about 262.4908441251.

The spelling of 18085998 in words is "eighteen million, eighty-five thousand, nine hundred ninety-eight".