12866588566821 has 72 divisors (see below), whose sum is σ = 21444608290560. Its totient is φ = 7418480256000.

The previous prime is 12866588566789. The next prime is 12866588566837.

12866588566821 is a `hidden beast` number, since 1 + 2 + 8 + 6 + 6 + 58 + 8 + 566 + 8 + 2 + 1 = 666.

12866588566821 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 12866588566821 - 2⁵ = 12866588566789 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12866588566821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12866588566721) 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, 1238140 + ... + 5221701.

Almost surely, 2^{12866588566821} is an apocalyptic number.

12866588566821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12866588566821 is a deficient number, since it is larger than the sum of its proper divisors (8578019723739).

12866588566821 is a wasteful number, since it uses less digits than its factorization.

12866588566821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6459959 (or 6459945 counting only the distinct ones).

The product of its digits is 530841600, while the sum is 72.

The spelling of 12866588566821 in words is "twelve trillion, eight hundred sixty-six billion, five hundred eighty-eight million, five hundred sixty-six thousand, eight hundred twenty-one".