18518505687 has 20 divisors (see below), whose sum is σ = 30178307016. Its totient is φ = 11223336240.

The previous prime is 18518505679. The next prime is 18518505749. The reversal of 18518505687 is 78650581581.

18518505687 is a `hidden beast` number, since 1 + 8 + 51 + 8 + 505 + 6 + 87 = 666.

It is not a de Polignac number, because 18518505687 - 2³ = 18518505679 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18518503687) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 10391088 + ... + 10392869.

Almost surely, 2^18518505687 is an apocalyptic number.

18518505687 is a deficient number, since it is larger than the sum of its proper divisors (11659801329).

18518505687 is a wasteful number, since it uses less digits than its factorization.

18518505687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20783980 (or 20783971 counting only the distinct ones).

The product of its (nonzero) digits is 2688000, while the sum is 54.

The spelling of 18518505687 in words is "eighteen billion, five hundred eighteen million, five hundred five thousand, six hundred eighty-seven".