18656438017 has 24 divisors (see below), whose sum is σ = 22660843392. Its totient is φ = 15285916800.

The previous prime is 18656437981. The next prime is 18656438039. The reversal of 18656438017 is 71083465681.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-18656438017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18656438417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2059017 + ... + 2068057.

It is an arithmetic number, because the mean of its divisors is an integer number (944201808).

Almost surely, 2^18656438017 is an apocalyptic number.

It is an amenable number.

18656438017 is a deficient number, since it is larger than the sum of its proper divisors (4004405375).

18656438017 is a wasteful number, since it uses less digits than its factorization.

18656438017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10909 (or 10902 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 49.

The spelling of 18656438017 in words is "eighteen billion, six hundred fifty-six million, four hundred thirty-eight thousand, seventeen".