128420500056 has 64 divisors (see below), whose sum is σ = 333125253120. Its totient is φ = 41211279360.

The previous prime is 128420500009. The next prime is 128420500111. The reversal of 128420500056 is 650005024821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 303580 + ... + 590763.

It is an arithmetic number, because the mean of its divisors is an integer number (5205082080).

Almost surely, 2^128420500056 is an apocalyptic number.

It is an amenable number.

128420500056 is an abundant number, since it is smaller than the sum of its proper divisors (204704753064).

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

128420500056 is a wasteful number, since it uses less digits than its factorization.

128420500056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 894576 (or 894572 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 33.

Adding to 128420500056 its reverse (650005024821), we get a palindrome (778425524877).

The spelling of 128420500056 in words is "one hundred twenty-eight billion, four hundred twenty million, five hundred thousand, fifty-six".