128681280 has 336 divisors, whose sum is σ = 545860224. Its totient is φ = 27095040.

The previous prime is 128681257. The next prime is 128681309. The reversal of 128681280 is 82186821.

It is a tau number, because it is divible by the number of its divisors (336).

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 47 ways as a sum of consecutive naturals, for example, 261835 + ... + 262325.

It is an arithmetic number, because the mean of its divisors is an integer number (1624584).

Almost surely, 2^128681280 is an apocalyptic number.

128681280 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 128681280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (272930112).

128681280 is an abundant number, since it is smaller than the sum of its proper divisors (417178944).

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

128681280 is a wasteful number, since it uses less digits than its factorization.

128681280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 534 (or 521 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 128681280 is about 11343.7771487278. Note that the first 3 decimals coincide. The cubic root of 128681280 is about 504.8609622788.

The spelling of 128681280 in words is "one hundred twenty-eight million, six hundred eighty-one thousand, two hundred eighty".