128197728 has 60 divisors (see below), whose sum is σ = 377033580. Its totient is φ = 42731712.

The previous prime is 128197721. The next prime is 128197739. The reversal of 128197728 is 827791821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128197721) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 22138 + ... + 27321.

It is an arithmetic number, because the mean of its divisors is an integer number (6283893).

Almost surely, 2^128197728 is an apocalyptic number.

128197728 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

128197728 is an abundant number, since it is smaller than the sum of its proper divisors (248835852).

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

128197728 is an equidigital number, since it uses as much as digits as its factorization.

128197728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49481 (or 49464 counting only the distinct ones).

The product of its digits is 112896, while the sum is 45.

The square root of 128197728 is about 11322.4435525199. The cubic root of 128197728 is about 504.2277881896.

The spelling of 128197728 in words is "one hundred twenty-eight million, one hundred ninety-seven thousand, seven hundred twenty-eight".