128968666649 has 2 divisors, whose sum is σ = 128968666650. Its totient is φ = 128968666648.

The previous prime is 128968666609. The next prime is 128968666699. The reversal of 128968666649 is 946666869821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99535833049 + 29432833600 = 315493^2 + 171560^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128968666649 is a prime.

It is not a weakly prime, because it can be changed into another prime (128968666609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64484333324 + 64484333325.

It is an arithmetic number, because the mean of its divisors is an integer number (64484333325).

Almost surely, 2^128968666649 is an apocalyptic number.

It is an amenable number.

128968666649 is a deficient number, since it is larger than the sum of its proper divisors (1).

128968666649 is an equidigital number, since it uses as much as digits as its factorization.

128968666649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 322486272, while the sum is 71.

The spelling of 128968666649 in words is "one hundred twenty-eight billion, nine hundred sixty-eight million, six hundred sixty-six thousand, six hundred forty-nine".