18520911609 has 8 divisors (see below), whose sum is σ = 24700531680. Its totient is φ = 12344282976.

The previous prime is 18520911593. The next prime is 18520911631. The reversal of 18520911609 is 90611902581.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18520911609 - 2⁴ = 18520911593 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18520911209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 733372 + ... + 758205.

It is an arithmetic number, because the mean of its divisors is an integer number (3087566460).

Almost surely, 2^18520911609 is an apocalyptic number.

It is an amenable number.

18520911609 is a deficient number, since it is larger than the sum of its proper divisors (6179620071).

18520911609 is a wasteful number, since it uses less digits than its factorization.

18520911609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1495719.

The product of its (nonzero) digits is 38880, while the sum is 42.

The spelling of 18520911609 in words is "eighteen billion, five hundred twenty million, nine hundred eleven thousand, six hundred nine".