128209728 has 56 divisors (see below), whose sum is σ = 353982528. Its totient is φ = 40877056.

The previous prime is 128209717. The next prime is 128209729. The reversal of 128209728 is 827902821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128209729) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 10101 + ... + 18932.

Almost surely, 2^128209728 is an apocalyptic number.

It is an amenable number.

128209728 is an abundant number, since it is smaller than the sum of its proper divisors (225772800).

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

128209728 is a wasteful number, since it uses less digits than its factorization.

128209728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29071 (or 29061 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 128209728 is about 11322.9734610658. The cubic root of 128209728 is about 504.2435205139.

The spelling of 128209728 in words is "one hundred twenty-eight million, two hundred nine thousand, seven hundred twenty-eight".