128865656 has 16 divisors (see below), whose sum is σ = 245230440. Its totient is φ = 63470880.

The previous prime is 128865643. The next prime is 128865673. The reversal of 128865656 is 656568821.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 128865656.

It is a congruent number.

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, 119675 + ... + 120746.

Almost surely, 2^128865656 is an apocalyptic number.

It is an amenable number.

128865656 is a deficient number, since it is larger than the sum of its proper divisors (116364784).

128865656 is a wasteful number, since it uses less digits than its factorization.

128865656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240494 (or 240490 counting only the distinct ones).

The product of its digits is 691200, while the sum is 47.

The square root of 128865656 is about 11351.9009861785. The cubic root of 128865656 is about 505.1019707165.

The spelling of 128865656 in words is "one hundred twenty-eight million, eight hundred sixty-five thousand, six hundred fifty-six".