128221025784 has 128 divisors (see below), whose sum is σ = 342374722560. Its totient is φ = 39929269248.

The previous prime is 128221025783. The next prime is 128221025789. The reversal of 128221025784 is 487520122821.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128221025783) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4135042 + ... + 4165934.

It is an arithmetic number, because the mean of its divisors is an integer number (2674802520).

Almost surely, 2^128221025784 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 128221025784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171187361280).

128221025784 is an abundant number, since it is smaller than the sum of its proper divisors (214153696776).

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

128221025784 is a wasteful number, since it uses less digits than its factorization.

128221025784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31101 (or 31097 counting only the distinct ones).

The product of its (nonzero) digits is 143360, while the sum is 42.

The spelling of 128221025784 in words is "one hundred twenty-eight billion, two hundred twenty-one million, twenty-five thousand, seven hundred eighty-four".