128657664 has 108 divisors (see below), whose sum is σ = 390608400. Its totient is φ = 40614912.

The previous prime is 128657663. The next prime is 128657681. The reversal of 128657664 is 466756821.

128657664 is a `hidden beast` number, since 12 + 8 + 6 + 576 + 64 = 666.

It is not an unprimeable number, because it can be changed into a prime (128657663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 42307 + ... + 45245.

Almost surely, 2^128657664 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 128657664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (195304200).

128657664 is an abundant number, since it is smaller than the sum of its proper divisors (261950736).

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

128657664 is a wasteful number, since it uses less digits than its factorization.

128657664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2980 (or 2963 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 128657664 is about 11342.7361778365. The cubic root of 128657664 is about 504.8300758232.

The spelling of 128657664 in words is "one hundred twenty-eight million, six hundred fifty-seven thousand, six hundred sixty-four".