18645952899 has 72 divisors (see below), whose sum is σ = 30153134064. Its totient is φ = 10216281600.

The previous prime is 18645952891. The next prime is 18645952909. The reversal of 18645952899 is 99825954681.

It is a happy number.

It is not a de Polignac number, because 18645952899 - 2³ = 18645952891 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18645952891) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 15072909 + ... + 15074145.

Almost surely, 2^18645952899 is an apocalyptic number.

18645952899 is a deficient number, since it is larger than the sum of its proper divisors (11507181165).

18645952899 is a wasteful number, since it uses less digits than its factorization.

18645952899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1397 (or 1349 counting only the distinct ones).

The product of its digits is 55987200, while the sum is 66.

The spelling of 18645952899 in words is "eighteen billion, six hundred forty-five million, nine hundred fifty-two thousand, eight hundred ninety-nine".