128761617409 has 2 divisors, whose sum is σ = 128761617410. Its totient is φ = 128761617408.

The previous prime is 128761617401. The next prime is 128761617449. The reversal of 128761617409 is 904716167821.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117342557809 + 11419059600 = 342553^2 + 106860^2 .

It is an emirp because it is prime and its reverse (904716167821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128761617409 - 2³ = 128761617401 is a prime.

It is not a weakly prime, because it can be changed into another prime (128761617401) 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, 64380808704 + 64380808705.

It is an arithmetic number, because the mean of its divisors is an integer number (64380808705).

Almost surely, 2^128761617409 is an apocalyptic number.

It is an amenable number.

128761617409 is a deficient number, since it is larger than the sum of its proper divisors (1).

128761617409 is an equidigital number, since it uses as much as digits as its factorization.

128761617409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1016064, while the sum is 52.

The spelling of 128761617409 in words is "one hundred twenty-eight billion, seven hundred sixty-one million, six hundred seventeen thousand, four hundred nine".