128665555 has 8 divisors (see below), whose sum is σ = 157684032. Its totient is φ = 100742208.

The previous prime is 128665543. The next prime is 128665577. The reversal of 128665555 is 555566821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128665555 - 2¹³ = 128657363 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 273522 + ... + 273991.

It is an arithmetic number, because the mean of its divisors is an integer number (19710504).

Almost surely, 2^128665555 is an apocalyptic number.

128665555 is a deficient number, since it is larger than the sum of its proper divisors (29018477).

128665555 is an equidigital number, since it uses as much as digits as its factorization.

128665555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547565.

The product of its digits is 360000, while the sum is 43.

The square root of 128665555 is about 11343.0840162629. The cubic root of 128665555 is about 504.8403965782.

The spelling of 128665555 in words is "one hundred twenty-eight million, six hundred sixty-five thousand, five hundred fifty-five".