18504889 has 4 divisors (see below), whose sum is σ = 19928356. Its totient is φ = 17081424.

The previous prime is 18504883. The next prime is 18504919. The reversal of 18504889 is 98840581.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98840581 = 7 ⋅14120083.

It can be written as a sum of positive squares in 2 ways, for example, as 9504889 + 9000000 = 3083^2 + 3000^2 .

It is a cyclic number.

It is not a de Polignac number, because 18504889 - 2⁹ = 18504377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18504883) 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 in 3 ways as a sum of consecutive naturals, for example, 711714 + ... + 711739.

It is an arithmetic number, because the mean of its divisors is an integer number (4982089).

Almost surely, 2^18504889 is an apocalyptic number.

It is an amenable number.

18504889 is a deficient number, since it is larger than the sum of its proper divisors (1423467).

18504889 is a wasteful number, since it uses less digits than its factorization.

18504889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1423466.

The product of its (nonzero) digits is 92160, while the sum is 43.

The square root of 18504889 is about 4301.7309306836. The cubic root of 18504889 is about 264.5019195285.

The spelling of 18504889 in words is "eighteen million, five hundred four thousand, eight hundred eighty-nine".