128656320 has 224 divisors, whose sum is σ = 449762880. Its totient is φ = 31150080.

The previous prime is 128656313. The next prime is 128656321. The reversal of 128656320 is 23656821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128656321) 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 31 ways as a sum of consecutive naturals, for example, 2109090 + ... + 2109150.

It is an arithmetic number, because the mean of its divisors is an integer number (2007870).

Almost surely, 2^128656320 is an apocalyptic number.

128656320 is a gapful number since it is divisible by the number (10) 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 128656320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224881440).

128656320 is an abundant number, since it is smaller than the sum of its proper divisors (321106560).

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

128656320 is an equidigital number, since it uses as much as digits as its factorization.

128656320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 128656320 is about 11342.6769327174. The cubic root of 128656320 is about 504.8283179438.

The spelling of 128656320 in words is "one hundred twenty-eight million, six hundred fifty-six thousand, three hundred twenty".