128728320 has 144 divisors (see below), whose sum is σ = 469956480. Its totient is φ = 29417472.

The previous prime is 128728319. The next prime is 128728331. The reversal of 128728320 is 23827821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24486 + ... + 29274.

Almost surely, 2^128728320 is an apocalyptic number.

128728320 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 128728320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (234978240).

128728320 is an abundant number, since it is smaller than the sum of its proper divisors (341228160).

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

128728320 is an equidigital number, since it uses as much as digits as its factorization.

128728320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4820 (or 4806 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 128728320 is about 11345.8503427465. The cubic root of 128728320 is about 504.9224728224.

The spelling of 128728320 in words is "one hundred twenty-eight million, seven hundred twenty-eight thousand, three hundred twenty".