128912220 has 72 divisors (see below), whose sum is σ = 393316560. Its totient is φ = 34176000.

The previous prime is 128912213. The next prime is 128912243. The reversal of 128912220 is 22219821.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30220 + ... + 34220.

It is an arithmetic number, because the mean of its divisors is an integer number (5462730).

Almost surely, 2^128912220 is an apocalyptic number.

128912220 is a gapful number since it is divisible by the number (10) 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 128912220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196658280).

128912220 is an abundant number, since it is smaller than the sum of its proper divisors (264404340).

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

128912220 is a wasteful number, since it uses less digits than its factorization.

128912220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4195 (or 4190 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 128912220 is about 11353.9517349688. The cubic root of 128912220 is about 505.1628008260.

The spelling of 128912220 in words is "one hundred twenty-eight million, nine hundred twelve thousand, two hundred twenty".