18049558 has 4 divisors (see below), whose sum is σ = 27074340. Its totient is φ = 9024778.

The previous prime is 18049543. The next prime is 18049561. The reversal of 18049558 is 85594081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 85594081 = 2207 ⋅38783.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 18049558.

It is a congruent number.

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, 4512388 + ... + 4512391.

It is an arithmetic number, because the mean of its divisors is an integer number (6768585).

Almost surely, 2^18049558 is an apocalyptic number.

18049558 is a deficient number, since it is larger than the sum of its proper divisors (9024782).

18049558 is an equidigital number, since it uses as much as digits as its factorization.

18049558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9024781.

The product of its (nonzero) digits is 57600, while the sum is 40.

The square root of 18049558 is about 4248.4771389287. The cubic root of 18049558 is about 262.3144351413.

The spelling of 18049558 in words is "eighteen million, forty-nine thousand, five hundred fifty-eight".