128665388 has 12 divisors (see below), whose sum is σ = 225615600. Its totient is φ = 64203792.

The previous prime is 128665357. The next prime is 128665423. The reversal of 128665388 is 883566821.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29963 + ... + 33986.

It is an arithmetic number, because the mean of its divisors is an integer number (18801300).

Almost surely, 2^128665388 is an apocalyptic number.

It is an amenable number.

128665388 is a deficient number, since it is larger than the sum of its proper divisors (96950212).

128665388 is a wasteful number, since it uses less digits than its factorization.

128665388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64456 (or 64454 counting only the distinct ones).

The product of its digits is 552960, while the sum is 47.

The square root of 128665388 is about 11343.0766549468. The cubic root of 128665388 is about 504.8401781608.

The spelling of 128665388 in words is "one hundred twenty-eight million, six hundred sixty-five thousand, three hundred eighty-eight".