128398649569 has 2 divisors, whose sum is σ = 128398649570. Its totient is φ = 128398649568.

The previous prime is 128398649557. The next prime is 128398649591. The reversal of 128398649569 is 965946893821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 105677006400 + 22721643169 = 325080^2 + 150737^2 .

It is a cyclic number.

It is not a de Polignac number, because 128398649569 - 2²⁹ = 127861778657 is a prime.

It is a super-2 number, since 2×128398649569² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 128398649498 and 128398649507.

It is not a weakly prime, because it can be changed into another prime (128398647569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64199324784 + 64199324785.

It is an arithmetic number, because the mean of its divisors is an integer number (64199324785).

Almost surely, 2^128398649569 is an apocalyptic number.

It is an amenable number.

128398649569 is a deficient number, since it is larger than the sum of its proper divisors (1).

128398649569 is an equidigital number, since it uses as much as digits as its factorization.

128398649569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 201553920, while the sum is 70.

The spelling of 128398649569 in words is "one hundred twenty-eight billion, three hundred ninety-eight million, six hundred forty-nine thousand, five hundred sixty-nine".