128731680 has 576 divisors, whose sum is σ = 581188608. Its totient is φ = 26127360.

The previous prime is 128731661. The next prime is 128731693. The reversal of 128731680 is 86137821.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2993739 + ... + 2993781.

It is an arithmetic number, because the mean of its divisors is an integer number (1009008).

Almost surely, 2^128731680 is an apocalyptic number.

128731680 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 128731680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (290594304).

128731680 is an abundant number, since it is smaller than the sum of its proper divisors (452456928).

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

128731680 is a wasteful number, since it uses less digits than its factorization.

128731680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 128731680 is about 11345.9984135377. The cubic root of 128731680 is about 504.9268658592.

Adding to 128731680 its sum of digits (36), we get a square (128731716 = 11346²).

The spelling of 128731680 in words is "one hundred twenty-eight million, seven hundred thirty-one thousand, six hundred eighty".