128261728 has 24 divisors (see below), whose sum is σ = 288589392. Its totient is φ = 54969216.

The previous prime is 128261701. The next prime is 128261737. The reversal of 128261728 is 827162821.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 286075 + ... + 286522.

It is an arithmetic number, because the mean of its divisors is an integer number (12024558).

Almost surely, 2^128261728 is an apocalyptic number.

It is an amenable number.

128261728 is an abundant number, since it is smaller than the sum of its proper divisors (160327664).

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

128261728 is an equidigital number, since it uses as much as digits as its factorization.

128261728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 572614 (or 572606 counting only the distinct ones).

The product of its digits is 21504, while the sum is 37.

The square root of 128261728 is about 11325.2694449183. The cubic root of 128261728 is about 504.3116825776.

The spelling of 128261728 in words is "one hundred twenty-eight million, two hundred sixty-one thousand, seven hundred twenty-eight".