18384638 has 4 divisors (see below), whose sum is σ = 27576960. Its totient is φ = 9192318.

The previous prime is 18384629. The next prime is 18384677. The reversal of 18384638 is 83648381.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83648381 = 17 ⋅4920493.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18384595 and 18384604.

It is a congruent number.

It is an unprimeable number.

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, 4596158 + ... + 4596161.

It is an arithmetic number, because the mean of its divisors is an integer number (6894240).

Almost surely, 2^18384638 is an apocalyptic number.

18384638 is a deficient number, since it is larger than the sum of its proper divisors (9192322).

18384638 is an equidigital number, since it uses as much as digits as its factorization.

18384638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9192321.

The product of its digits is 110592, while the sum is 41.

The square root of 18384638 is about 4287.7311016434. The cubic root of 18384638 is about 263.9277331275.

The spelling of 18384638 in words is "eighteen million, three hundred eighty-four thousand, six hundred thirty-eight".