18043138 has 4 divisors (see below), whose sum is σ = 27064710. Its totient is φ = 9021568.

The previous prime is 18043099. The next prime is 18043163. The reversal of 18043138 is 83134081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83134081 = 103 ⋅807127.

It can be written as a sum of positive squares in only one way, i.e., 15108769 + 2934369 = 3887^2 + 1713^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4510783 + ... + 4510786.

Almost surely, 2^18043138 is an apocalyptic number.

18043138 is a deficient number, since it is larger than the sum of its proper divisors (9021572).

18043138 is an equidigital number, since it uses as much as digits as its factorization.

18043138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9021571.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 18043138 is about 4247.7215068787. The cubic root of 18043138 is about 262.2833308085.

It can be divided in two parts, 18043 and 138, that added together give a palindrome (18181).

The spelling of 18043138 in words is "eighteen million, forty-three thousand, one hundred thirty-eight".