18915368217 has 8 divisors (see below), whose sum is σ = 25333588224. Its totient is φ = 12553696848.

The previous prime is 18915368111. The next prime is 18915368237. The reversal of 18915368217 is 71286351981.

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

It is not a de Polignac number, because 18915368217 - 2¹⁹ = 18914843929 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18915368217.

It is not an unprimeable number, because it can be changed into a prime (18915368237) 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, 14136378 + ... + 14137715.

It is an arithmetic number, because the mean of its divisors is an integer number (3166698528).

Almost surely, 2^18915368217 is an apocalyptic number.

It is an amenable number.

18915368217 is a deficient number, since it is larger than the sum of its proper divisors (6418220007).

18915368217 is a wasteful number, since it uses less digits than its factorization.

18915368217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28274319.

The product of its digits is 725760, while the sum is 51.

The spelling of 18915368217 in words is "eighteen billion, nine hundred fifteen million, three hundred sixty-eight thousand, two hundred seventeen".