128666928 has 40 divisors (see below), whose sum is σ = 357959728. Its totient is φ = 39589632.

The previous prime is 128666921. The next prime is 128666929. The reversal of 128666928 is 829666821.

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 (128666921) 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, 102475 + ... + 103722.

Almost surely, 2^128666928 is an apocalyptic number.

It is an amenable number.

128666928 is an abundant number, since it is smaller than the sum of its proper divisors (229292800).

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

128666928 is a wasteful number, since it uses less digits than its factorization.

128666928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206221 (or 206215 counting only the distinct ones).

The product of its digits is 497664, while the sum is 48.

The square root of 128666928 is about 11343.1445375610. The cubic root of 128666928 is about 504.8421923020.

The spelling of 128666928 in words is "one hundred twenty-eight million, six hundred sixty-six thousand, nine hundred twenty-eight".