18664215478271 has 48 divisors (see below), whose sum is σ = 21161650406400. Its totient is φ = 16308456278400.

The previous prime is 18664215478241. The next prime is 18664215478313. The reversal of 18664215478271 is 17287451246681.

It is a de Polignac number, because none of the positive numbers 2^k-18664215478271 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18664215478241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11599884515 + ... + 11599886123.

It is an arithmetic number, because the mean of its divisors is an integer number (440867716800).

Almost surely, 2^{18664215478271} is an apocalyptic number.

18664215478271 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

18664215478271 is a deficient number, since it is larger than the sum of its proper divisors (2497434928129).

18664215478271 is a wasteful number, since it uses less digits than its factorization.

18664215478271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2908 (or 2709 counting only the distinct ones).

The product of its digits is 36126720, while the sum is 62.

The spelling of 18664215478271 in words is "eighteen trillion, six hundred sixty-four billion, two hundred fifteen million, four hundred seventy-eight thousand, two hundred seventy-one".