18398 has 4 divisors (see below), whose sum is σ = 27600. Its totient is φ = 9198.

The previous prime is 18397. The next prime is 18401. The reversal of 18398 is 89381.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 18398.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4598 + ... + 4601.

It is an arithmetic number, because the mean of its divisors is an integer number (6900).

2¹⁸³⁹⁸ is an apocalyptic number.

18398 is a deficient number, since it is larger than the sum of its proper divisors (9202).

18398 is an equidigital number, since it uses as much as digits as its factorization.

18398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9201.

The product of its digits is 1728, while the sum is 29.

The square root of 18398 is about 135.6392273644. The cubic root of 18398 is about 26.3991658751.

The spelling of 18398 in words is "eighteen thousand, three hundred ninety-eight".