12688385981 has 2 divisors, whose sum is σ = 12688385982. Its totient is φ = 12688385980.

The previous prime is 12688385929. The next prime is 12688386001. The reversal of 12688385981 is 18958388621.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11477693956 + 1210692025 = 107134^2 + 34795^2 .

It is an emirp because it is prime and its reverse (18958388621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12688385981 - 2⁶ = 12688385917 is a prime.

It is a super-2 number, since 2×12688385981² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12688385981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12688385911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6344192990 + 6344192991.

It is an arithmetic number, because the mean of its divisors is an integer number (6344192991).

Almost surely, 2^12688385981 is an apocalyptic number.

It is an amenable number.

12688385981 is a deficient number, since it is larger than the sum of its proper divisors (1).

12688385981 is an equidigital number, since it uses as much as digits as its factorization.

12688385981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6635520, while the sum is 59.

The spelling of 12688385981 in words is "twelve billion, six hundred eighty-eight million, three hundred eighty-five thousand, nine hundred eighty-one".