18000238 has 4 divisors (see below), whose sum is σ = 27000360. Its totient is φ = 9000118.

The previous prime is 18000221. The next prime is 18000259. The reversal of 18000238 is 83200081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83200081 = 7507 ⋅11083.

It is a Smith number, since the sum of its digits (22) 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 an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4500058 + ... + 4500061.

It is an arithmetic number, because the mean of its divisors is an integer number (6750090).

Almost surely, 2^18000238 is an apocalyptic number.

18000238 is a deficient number, since it is larger than the sum of its proper divisors (9000122).

18000238 is an equidigital number, since it uses as much as digits as its factorization.

18000238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9000121.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 18000238 is about 4242.6687355956. The cubic root of 18000238 is about 262.0752944833.

The spelling of 18000238 in words is "eighteen million, two hundred thirty-eight", and thus it is an aban number.