12748007815721 has 2 divisors, whose sum is σ = 12748007815722. Its totient is φ = 12748007815720.

The previous prime is 12748007815681. The next prime is 12748007815769. The reversal of 12748007815721 is 12751870084721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10710925290025 + 2037082525696 = 3272755^2 + 1427264^2 .

It is a cyclic number.

It is not a de Polignac number, because 12748007815721 - 2⁶ = 12748007815657 is a prime.

It is not a weakly prime, because it can be changed into another prime (12748007805721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6374003907860 + 6374003907861.

It is an arithmetic number, because the mean of its divisors is an integer number (6374003907861).

Almost surely, 2^{12748007815721} is an apocalyptic number.

It is an amenable number.

12748007815721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12748007815721 is an equidigital number, since it uses as much as digits as its factorization.

12748007815721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1756160, while the sum is 53.

The spelling of 12748007815721 in words is "twelve trillion, seven hundred forty-eight billion, seven million, eight hundred fifteen thousand, seven hundred twenty-one".