128655680 has 28 divisors (see below), whose sum is σ = 306362100. Its totient is φ = 51462144.

The previous prime is 128655679. The next prime is 128655701. The reversal of 128655680 is 86556821.

It can be written as a sum of positive squares in 2 ways, for example, as 33085504 + 95570176 = 5752^2 + 9776^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 200705 + ... + 201344.

Almost surely, 2^128655680 is an apocalyptic number.

128655680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128655680 is an abundant number, since it is smaller than the sum of its proper divisors (177706420).

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

128655680 is an equidigital number, since it uses as much as digits as its factorization.

128655680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402066 (or 402056 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 41.

The square root of 128655680 is about 11342.6487206472. The cubic root of 128655680 is about 504.8274808540.

The spelling of 128655680 in words is "one hundred twenty-eight million, six hundred fifty-five thousand, six hundred eighty".