18564918438 has 32 divisors (see below), whose sum is σ = 40840048512. Its totient is φ = 5625730440.

The previous prime is 18564918319. The next prime is 18564918439. The reversal of 18564918438 is 83481946581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18564918439) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1154356 + ... + 1170327.

It is an arithmetic number, because the mean of its divisors is an integer number (1276251516).

Almost surely, 2^18564918438 is an apocalyptic number.

18564918438 is an abundant number, since it is smaller than the sum of its proper divisors (22275130074).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18564918438 is a wasteful number, since it uses less digits than its factorization.

18564918438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2324721 (or 2324699 counting only the distinct ones).

The product of its digits is 6635520, while the sum is 57.

It can be divided in two parts, 1856 and 4918438, that added together give a palindrome (4920294).

The spelling of 18564918438 in words is "eighteen billion, five hundred sixty-four million, nine hundred eighteen thousand, four hundred thirty-eight".