18002398 has 4 divisors (see below), whose sum is σ = 27003600. Its totient is φ = 9001198.

The previous prime is 18002393. The next prime is 18002401. The reversal of 18002398 is 89320081.

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

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18002393) by changing a digit.

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 as a sum of consecutive naturals, namely, 4500598 + ... + 4500601.

It is an arithmetic number, because the mean of its divisors is an integer number (6750900).

Almost surely, 2^18002398 is an apocalyptic number.

18002398 is a deficient number, since it is larger than the sum of its proper divisors (9001202).

18002398 is an equidigital number, since it uses as much as digits as its factorization.

18002398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9001201.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 18002398 is about 4242.9232847177. The cubic root of 18002398 is about 262.0857769372.

The spelling of 18002398 in words is "eighteen million, two thousand, three hundred ninety-eight".