68146906721 has 2 divisors, whose sum is σ = 68146906722. Its totient is φ = 68146906720.

The previous prime is 68146906717. The next prime is 68146906813. The reversal of 68146906721 is 12760964186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40346346496 + 27800560225 = 200864^2 + 166735^2 .

It is a cyclic number.

It is not a de Polignac number, because 68146906721 - 2² = 68146906717 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 68146906721.

It is not a weakly prime, because it can be changed into another prime (68146902721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34073453360 + 34073453361.

It is an arithmetic number, because the mean of its divisors is an integer number (34073453361).

Almost surely, 2^68146906721 is an apocalyptic number.

It is an amenable number.

68146906721 is a deficient number, since it is larger than the sum of its proper divisors (1).

68146906721 is an equidigital number, since it uses as much as digits as its factorization.

68146906721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 870912, while the sum is 50.

The spelling of 68146906721 in words is "sixty-eight billion, one hundred forty-six million, nine hundred six thousand, seven hundred twenty-one".