12640113721 has 2 divisors, whose sum is σ = 12640113722. Its totient is φ = 12640113720.

The previous prime is 12640113637. The next prime is 12640113757. The reversal of 12640113721 is 12731104621.

12640113721 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 can be written as a sum of positive squares in only one way, i.e., 12098900025 + 541213696 = 109995^2 + 23264^2 .

It is a cyclic number.

It is not a de Polignac number, because 12640113721 - 2¹⁹ = 12639589433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12640113721.

It is not a weakly prime, because it can be changed into another prime (12640113821) 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, 6320056860 + 6320056861.

It is an arithmetic number, because the mean of its divisors is an integer number (6320056861).

Almost surely, 2^12640113721 is an apocalyptic number.

It is an amenable number.

12640113721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12640113721 is an equidigital number, since it uses as much as digits as its factorization.

12640113721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 28.

The spelling of 12640113721 in words is "twelve billion, six hundred forty million, one hundred thirteen thousand, seven hundred twenty-one".