12643656884 has 6 divisors (see below), whose sum is σ = 22126399554. Its totient is φ = 6321828440.

The previous prime is 12643656847. The next prime is 12643656887. The reversal of 12643656884 is 48865634621.

It can be written as a sum of positive squares in only one way, i.e., 12095160484 + 548496400 = 109978^2 + 23420^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12643656887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1580457107 + ... + 1580457114.

It is an arithmetic number, because the mean of its divisors is an integer number (3687733259).

Almost surely, 2^12643656884 is an apocalyptic number.

It is an amenable number.

12643656884 is a deficient number, since it is larger than the sum of its proper divisors (9482742670).

12643656884 is a wasteful number, since it uses less digits than its factorization.

12643656884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3160914225 (or 3160914223 counting only the distinct ones).

The product of its digits is 6635520, while the sum is 53.

The spelling of 12643656884 in words is "twelve billion, six hundred forty-three million, six hundred fifty-six thousand, eight hundred eighty-four".