18189561868 has 24 divisors (see below), whose sum is σ = 33228891360. Its totient is φ = 8695906560.

The previous prime is 18189561851. The next prime is 18189561869. The reversal of 18189561868 is 86816598181.

It is not an unprimeable number, because it can be changed into a prime (18189561869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 202138 + ... + 277918.

It is an arithmetic number, because the mean of its divisors is an integer number (1384537140).

Almost surely, 2^18189561868 is an apocalyptic number.

It is an amenable number.

18189561868 is a deficient number, since it is larger than the sum of its proper divisors (15039329492).

18189561868 is a wasteful number, since it uses less digits than its factorization.

18189561868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78417 (or 78415 counting only the distinct ones).

The product of its digits is 6635520, while the sum is 61.

The spelling of 18189561868 in words is "eighteen billion, one hundred eighty-nine million, five hundred sixty-one thousand, eight hundred sixty-eight".