18549789909 has 24 divisors (see below), whose sum is σ = 29440208160. Its totient is φ = 10353367584.

The previous prime is 18549789857. The next prime is 18549789911. The reversal of 18549789909 is 90998794581.

It is not a de Polignac number, because 18549789909 - 2²⁵ = 18516235477 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18549789949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1460994 + ... + 1473635.

It is an arithmetic number, because the mean of its divisors is an integer number (1226675340).

Almost surely, 2^18549789909 is an apocalyptic number.

It is an amenable number.

18549789909 is a deficient number, since it is larger than the sum of its proper divisors (10890418251).

18549789909 is a wasteful number, since it uses less digits than its factorization.

18549789909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2934689 (or 2934682 counting only the distinct ones).

The product of its (nonzero) digits is 58786560, while the sum is 69.

The spelling of 18549789909 in words is "eighteen billion, five hundred forty-nine million, seven hundred eighty-nine thousand, nine hundred nine".