128609731584 has 220 divisors, whose sum is σ = 385176072204. Its totient is φ = 42744692736.

The previous prime is 128609731531. The next prime is 128609731609. The reversal of 128609731584 is 485137906821.

128609731584 is a `hidden beast` number, since 1 + 28 + 6 + 0 + 9 + 7 + 31 + 584 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 64231833600 + 64377897984 = 253440^2 + 253728^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 128609731584.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 30936034 + ... + 30940190.

It is a 1-persistent number, because it is pandigital, but 2⋅128609731584 = 257219463168 is not.

Almost surely, 2^128609731584 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128609731584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192588036102).

128609731584 is an abundant number, since it is smaller than the sum of its proper divisors (256566340620).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

128609731584 is an equidigital number, since it uses as much as digits as its factorization.

128609731584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4562 (or 4535 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 128609731584 in words is "one hundred twenty-eight billion, six hundred nine million, seven hundred thirty-one thousand, five hundred eighty-four".