12891299656777 has 2 divisors, whose sum is σ = 12891299656778. Its totient is φ = 12891299656776.

The previous prime is 12891299656747. The next prime is 12891299656783. The reversal of 12891299656777 is 77765699219821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12890261270601 + 1038386176 = 3590301^2 + 32224^2 .

It is a cyclic number.

It is not a de Polignac number, because 12891299656777 - 2⁷ = 12891299656649 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12891299656697 and 12891299656706.

It is not a weakly prime, because it can be changed into another prime (12891299656747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6445649828388 + 6445649828389.

It is an arithmetic number, because the mean of its divisors is an integer number (6445649828389).

Almost surely, 2^{12891299656777} is an apocalyptic number.

It is an amenable number.

12891299656777 is a deficient number, since it is larger than the sum of its proper divisors (1).

12891299656777 is an equidigital number, since it uses as much as digits as its factorization.

12891299656777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440270720, while the sum is 79.

The spelling of 12891299656777 in words is "twelve trillion, eight hundred ninety-one billion, two hundred ninety-nine million, six hundred fifty-six thousand, seven hundred seventy-seven".