128781409680 has 1280 divisors, whose sum is σ = 601881477120. Its totient is φ = 24485068800.

The previous prime is 128781409661. The next prime is 128781409723. The reversal of 128781409680 is 86904187821.

128781409680 is a `hidden beast` number, since 1 + 2 + 87 + 81 + 409 + 6 + 80 = 666.

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

It is an unprimeable number.

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 255 ways as a sum of consecutive naturals, for example, 104614665 + ... + 104615895.

It is an arithmetic number, because the mean of its divisors is an integer number (470219904).

Almost surely, 2^128781409680 is an apocalyptic number.

128781409680 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 128781409680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (300940738560).

128781409680 is an abundant number, since it is smaller than the sum of its proper divisors (473100067440).

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

128781409680 is a wasteful number, since it uses less digits than its factorization.

128781409680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1325 (or 1313 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 54.

The spelling of 128781409680 in words is "one hundred twenty-eight billion, seven hundred eighty-one million, four hundred nine thousand, six hundred eighty".