18389243 has 4 divisors (see below), whose sum is σ = 18690768. Its totient is φ = 18087720.

The previous prime is 18389237. The next prime is 18389263. The reversal of 18389243 is 34298381.

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

It is not a de Polignac number, because 18389243 - 2⁴ = 18389227 is a prime.

It is a super-2 number, since 2×18389243² = 676328516226098, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18389197 and 18389206.

It is not an unprimeable number, because it can be changed into a prime (18389263) 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 in 3 ways as a sum of consecutive naturals, for example, 150671 + ... + 150792.

It is an arithmetic number, because the mean of its divisors is an integer number (4672692).

Almost surely, 2^18389243 is an apocalyptic number.

18389243 is a deficient number, since it is larger than the sum of its proper divisors (301525).

18389243 is an equidigital number, since it uses as much as digits as its factorization.

18389243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301524.

The product of its digits is 41472, while the sum is 38.

The square root of 18389243 is about 4288.2680653149. The cubic root of 18389243 is about 263.9497675700.

The spelling of 18389243 in words is "eighteen million, three hundred eighty-nine thousand, two hundred forty-three".