128685438720 has 360 divisors, whose sum is σ = 461298831840. Its totient is φ = 34253660160.

The previous prime is 128685438691. The next prime is 128685438727. The reversal of 128685438720 is 27834586821.

128685438720 is a `hidden beast` number, since 1 + 28 + 6 + 8 + 543 + 8 + 72 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128685438727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 97562221 + ... + 97563539.

It is an arithmetic number, because the mean of its divisors is an integer number (1281385644).

Almost surely, 2^128685438720 is an apocalyptic number.

128685438720 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 128685438720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230649415920).

128685438720 is an abundant number, since it is smaller than the sum of its proper divisors (332613393120).

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

128685438720 is an equidigital number, since it uses as much as digits as its factorization.

128685438720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2293 (or 2270 counting only the distinct ones).

The product of its (nonzero) digits is 5160960, while the sum is 54.

The spelling of 128685438720 in words is "one hundred twenty-eight billion, six hundred eighty-five million, four hundred thirty-eight thousand, seven hundred twenty".