128909568 has 72 divisors (see below), whose sum is σ = 349671168. Its totient is φ = 42145792.

The previous prime is 128909537. The next prime is 128909569. The reversal of 128909568 is 865909821.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128909569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39121 + ... + 42287.

It is an arithmetic number, because the mean of its divisors is an integer number (4856544).

Almost surely, 2^128909568 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128909568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174835584).

128909568 is an abundant number, since it is smaller than the sum of its proper divisors (220761600).

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

128909568 is an equidigital number, since it uses as much as digits as its factorization.

128909568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3239 (or 3225 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 48.

The square root of 128909568 is about 11353.8349468362. The cubic root of 128909568 is about 505.1593367093.

The spelling of 128909568 in words is "one hundred twenty-eight million, nine hundred nine thousand, five hundred sixty-eight".