128320 has 28 divisors (see below), whose sum is σ = 306324. Its totient is φ = 51200.

The previous prime is 128311. The next prime is 128321. The reversal of 128320 is 23821.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 97344 + 30976 = 312^2 + 176^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 128294 and 128303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128321) by changing a digit.

128320 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 120 + ... + 520.

2¹²⁸³²⁰ is an apocalyptic number.

128320 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 128320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (153162).

128320 is an abundant number, since it is smaller than the sum of its proper divisors (178004).

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

128320 is an equidigital number, since it uses as much as digits as its factorization.

128320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 128320 is about 358.2178108358. The cubic root of 128320 is about 50.4388044148.

The spelling of 128320 in words is "one hundred twenty-eight thousand, three hundred twenty".