128800056 has 64 divisors (see below), whose sum is σ = 401460480. Its totient is φ = 33454080.

The previous prime is 128800051. The next prime is 128800079. The reversal of 128800056 is 650008821.

It is a junction number, because it is equal to n+sod(n) for n = 128799996 and 128800032.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128800051) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33001 + ... + 36696.

It is an arithmetic number, because the mean of its divisors is an integer number (6272820).

Almost surely, 2^128800056 is an apocalyptic number.

It is an amenable number.

128800056 is an abundant number, since it is smaller than the sum of its proper divisors (272660424).

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

128800056 is a wasteful number, since it uses less digits than its factorization.

128800056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69724 (or 69720 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 30.

The square root of 128800056 is about 11349.0112344644. The cubic root of 128800056 is about 505.0162475575.

Adding to 128800056 its reverse (650008821), we get a palindrome (778808877).

The spelling of 128800056 in words is "one hundred twenty-eight million, eight hundred thousand, fifty-six".