128609568 has 36 divisors (see below), whose sum is σ = 365734278. Its totient is φ = 42869760.

The previous prime is 128609567. The next prime is 128609597. The reversal of 128609568 is 865906821.

128609568 is a `hidden beast` number, since 1 + 2 + 86 + 0 + 9 + 568 = 666.

It can be written as a sum of positive squares in only one way, i.e., 104284944 + 24324624 = 10212^2 + 4932^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×128609568² = 33080841962293248, which contains 22 as substring.

It is a zygodrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (128609561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 222993 + ... + 223568.

Almost surely, 2^128609568 is an apocalyptic number.

128609568 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

128609568 is an abundant number, since it is smaller than the sum of its proper divisors (237124710).

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

128609568 is a wasteful number, since it uses less digits than its factorization.

128609568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446577 (or 446566 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 45.

The square root of 128609568 is about 11340.6158562928. The cubic root of 128609568 is about 504.7671612307.

The spelling of 128609568 in words is "one hundred twenty-eight million, six hundred nine thousand, five hundred sixty-eight".