128688768 has 144 divisors (see below), whose sum is σ = 401598990. Its totient is φ = 39536640.

The previous prime is 128688757. The next prime is 128688799. The reversal of 128688768 is 867886821.

It can be written as a sum of positive squares in 3 ways, for example, as 84492864 + 44195904 = 9192^2 + 6648^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 194358 + ... + 195018.

Almost surely, 2^128688768 is an apocalyptic number.

128688768 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128688768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (200799495).

128688768 is an abundant number, since it is smaller than the sum of its proper divisors (272910222).

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

128688768 is a wasteful number, since it uses less digits than its factorization.

128688768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707 (or 679 counting only the distinct ones).

The product of its digits is 2064384, while the sum is 54.

The square root of 128688768 is about 11344.1071927235. The cubic root of 128688768 is about 504.8707547562.

The spelling of 128688768 in words is "one hundred twenty-eight million, six hundred eighty-eight thousand, seven hundred sixty-eight".