12666541937891 has 2 divisors, whose sum is σ = 12666541937892. Its totient is φ = 12666541937890.

The previous prime is 12666541937831. The next prime is 12666541937923. The reversal of 12666541937891 is 19873914566621.

It is a happy number.

12666541937891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12666541937891 - 2¹⁴ = 12666541921507 is a prime.

It is not a weakly prime, because it can be changed into another prime (12666541937831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6333270968945 + 6333270968946.

It is an arithmetic number, because the mean of its divisors is an integer number (6333270968946).

Almost surely, 2^{12666541937891} is an apocalyptic number.

12666541937891 is a deficient number, since it is larger than the sum of its proper divisors (1).

12666541937891 is an equidigital number, since it uses as much as digits as its factorization.

12666541937891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 117573120, while the sum is 68.

The spelling of 12666541937891 in words is "twelve trillion, six hundred sixty-six billion, five hundred forty-one million, nine hundred thirty-seven thousand, eight hundred ninety-one".