129128757517 has 2 divisors, whose sum is σ = 129128757518. Its totient is φ = 129128757516.

The previous prime is 129128757427. The next prime is 129128757551. The reversal of 129128757517 is 715757821921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110105176041 + 19023581476 = 331821^2 + 137926^2 .

It is a cyclic number.

It is not a de Polignac number, because 129128757517 - 2¹⁹ = 129128233229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129128757587) 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, 64564378758 + 64564378759.

It is an arithmetic number, because the mean of its divisors is an integer number (64564378759).

Almost surely, 2^129128757517 is an apocalyptic number.

It is an amenable number.

129128757517 is a deficient number, since it is larger than the sum of its proper divisors (1).

129128757517 is an equidigital number, since it uses as much as digits as its factorization.

129128757517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2469600, while the sum is 55.

The spelling of 129128757517 in words is "one hundred twenty-nine billion, one hundred twenty-eight million, seven hundred fifty-seven thousand, five hundred seventeen".