128905560 has 384 divisors, whose sum is σ = 530496000. Its totient is φ = 27260928.

The previous prime is 128905559. The next prime is 128905603. The reversal of 128905560 is 65509821.

It is a happy number.

128905560 is a `hidden beast` number, since 1 + 2 + 8 + 90 + 5 + 560 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2184811 + ... + 2184869.

It is an arithmetic number, because the mean of its divisors is an integer number (1381500).

Almost surely, 2^128905560 is an apocalyptic number.

128905560 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 128905560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265248000).

128905560 is an abundant number, since it is smaller than the sum of its proper divisors (401590440).

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

128905560 is a wasteful number, since it uses less digits than its factorization.

128905560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 93 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 128905560 is about 11353.6584412250. The cubic root of 128905560 is about 505.1541012572.

Adding to 128905560 its sum of digits (36), we get a triangular number (128905596 = T₁₆₀₅₆).

The spelling of 128905560 in words is "one hundred twenty-eight million, nine hundred five thousand, five hundred sixty".