18386138 has 4 divisors (see below), whose sum is σ = 27579210. Its totient is φ = 9193068.

The previous prime is 18386107. The next prime is 18386149. The reversal of 18386138 is 83168381.

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

It can be written as a sum of positive squares in only one way, i.e., 15816529 + 2569609 = 3977^2 + 1603^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4596533 + ... + 4596536.

Almost surely, 2^18386138 is an apocalyptic number.

18386138 is a deficient number, since it is larger than the sum of its proper divisors (9193072).

18386138 is an equidigital number, since it uses as much as digits as its factorization.

18386138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9193071.

The product of its digits is 27648, while the sum is 38.

The square root of 18386138 is about 4287.9060157611. The cubic root of 18386138 is about 263.9349108743.

The spelling of 18386138 in words is "eighteen million, three hundred eighty-six thousand, one hundred thirty-eight".