128617628689 has 9 divisors (see below), whose sum is σ = 141377432329. Its totient is φ = 116921530660.

The previous prime is 128617628617. The next prime is 128617628693. The reversal of 128617628689 is 986826716821.

It is a happy number.

The square root of 128617628689 is 358633.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 128617628689 - 2⁹ = 128617628177 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128617628689.

It is not an unprimeable number, because it can be changed into a prime (128617628989) 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 in 8 ways as a sum of consecutive naturals, for example, 3928662 + ... + 3961264.

Almost surely, 2^128617628689 is an apocalyptic number.

128617628689 is the 358633-rd square number.

128617628689 is the 179317-th centered octagonal number.

It is an amenable number.

128617628689 is a deficient number, since it is larger than the sum of its proper divisors (12759803640).

128617628689 is an frugal number, since it uses more digits than its factorization.

128617628689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65228 (or 32614 counting only the distinct ones).

The product of its digits is 27869184, while the sum is 64.

Multiplying 128617628689 by its sum of digits (64), we get a square (8231528236096 = 2869064²).

The spelling of 128617628689 in words is "one hundred twenty-eight billion, six hundred seventeen million, six hundred twenty-eight thousand, six hundred eighty-nine".