128873728 has 18 divisors (see below), whose sum is σ = 257244554. Its totient is φ = 64436736.

The previous prime is 128873699. The next prime is 128873729. The reversal of 128873728 is 827378821.

It can be written as a sum of positive squares in only one way, i.e., 126157824 + 2715904 = 11232^2 + 1648^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128873729) by changing a digit.

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 as a sum of consecutive naturals, namely, 251451 + ... + 251962.

Almost surely, 2^128873728 is an apocalyptic number.

It is an amenable number.

128873728 is a deficient number, since it is larger than the sum of its proper divisors (128370826).

128873728 is an frugal number, since it uses more digits than its factorization.

128873728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503429 (or 503415 counting only the distinct ones).

The product of its digits is 301056, while the sum is 46.

The square root of 128873728 is about 11352.2565157769. The cubic root of 128873728 is about 505.1125168364.

The spelling of 128873728 in words is "one hundred twenty-eight million, eight hundred seventy-three thousand, seven hundred twenty-eight".