18998 has 16 divisors (see below), whose sum is σ = 34560. Its totient is φ = 7656.

The previous prime is 18979. The next prime is 19001. The reversal of 18998 is 89981.

It is a happy number.

It is a Curzon number.

It is a nialpdrome in base 13.

It is a zygodrome in base 3 and base 13.

It is a congruent number.

It is an unprimeable number.

18998 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 293 + ... + 351.

It is an arithmetic number, because the mean of its divisors is an integer number (2160).

2¹⁸⁹⁹⁸ is an apocalyptic number.

18998 is a deficient number, since it is larger than the sum of its proper divisors (15562).

18998 is a wasteful number, since it uses less digits than its factorization.

18998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91.

The product of its digits is 5184, while the sum is 35.

The square root of 18998 is about 137.8332325675. The cubic root of 18998 is about 26.6830801731.

The spelling of 18998 in words is "eighteen thousand, nine hundred ninety-eight".