128281680 has 60 divisors (see below), whose sum is σ = 430815060. Its totient is φ = 34208256.

The previous prime is 128281679. The next prime is 128281687. The reversal of 128281680 is 86182821.

It can be written as a sum of positive squares in 2 ways, for example, as 38638656 + 89643024 = 6216^2 + 9468^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-3 number, since 3×128281680³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128281687) 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 11 ways as a sum of consecutive naturals, for example, 88365 + ... + 89804.

It is an arithmetic number, because the mean of its divisors is an integer number (7180251).

Almost surely, 2^128281680 is an apocalyptic number.

128281680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128281680 is an abundant number, since it is smaller than the sum of its proper divisors (302533380).

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

128281680 is a wasteful number, since it uses less digits than its factorization.

128281680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178188 (or 178179 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 128281680 is about 11326.1502727096. The cubic root of 128281680 is about 504.3378309467.

The spelling of 128281680 in words is "one hundred twenty-eight million, two hundred eighty-one thousand, six hundred eighty".