18338986 has 4 divisors (see below), whose sum is σ = 27508482. Its totient is φ = 9169492.

The previous prime is 18338951. The next prime is 18338989. The reversal of 18338986 is 68983381.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68983381 = 601 ⋅114781.

It can be written as a sum of positive squares in only one way, i.e., 16556761 + 1782225 = 4069^2 + 1335^2 .

It is not an unprimeable number, because it can be changed into a prime (18338989) 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, 4584745 + ... + 4584748.

Almost surely, 2^18338986 is an apocalyptic number.

18338986 is a deficient number, since it is larger than the sum of its proper divisors (9169496).

18338986 is an equidigital number, since it uses as much as digits as its factorization.

18338986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9169495.

The product of its digits is 248832, while the sum is 46.

The square root of 18338986 is about 4282.4042312701. The cubic root of 18338986 is about 263.7090937810.

The spelling of 18338986 in words is "eighteen million, three hundred thirty-eight thousand, nine hundred eighty-six".