128557056 has 56 divisors (see below), whose sum is σ = 342863424. Its totient is φ = 42844160.

The previous prime is 128557027. The next prime is 128557067. The reversal of 128557056 is 650755821.

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, 21961 + ... + 27191.

Almost surely, 2^128557056 is an apocalyptic number.

128557056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 128557056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171431712).

128557056 is an abundant number, since it is smaller than the sum of its proper divisors (214306368).

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

128557056 is an frugal number, since it uses more digits than its factorization.

128557056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5260 (or 5236 counting only the distinct ones).

The product of its (nonzero) digits is 84000, while the sum is 39.

The square root of 128557056 is about 11338.3004017357. The cubic root of 128557056 is about 504.6984521345.

The spelling of 128557056 in words is "one hundred twenty-eight million, five hundred fifty-seven thousand, fifty-six".