128666207 has 4 divisors (see below), whose sum is σ = 129804960. Its totient is φ = 127527456.

The previous prime is 128666189. The next prime is 128666221. The reversal of 128666207 is 702666821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128666207 - 2⁸ = 128665951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128666227) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 569207 + ... + 569432.

It is an arithmetic number, because the mean of its divisors is an integer number (32451240).

Almost surely, 2^128666207 is an apocalyptic number.

128666207 is a deficient number, since it is larger than the sum of its proper divisors (1138753).

128666207 is a wasteful number, since it uses less digits than its factorization.

128666207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1138752.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 128666207 is about 11343.1127562059. The cubic root of 128666207 is about 504.8412493197.

The spelling of 128666207 in words is "one hundred twenty-eight million, six hundred sixty-six thousand, two hundred seven".