128728401 has 32 divisors (see below), whose sum is σ = 190080000. Its totient is φ = 77128128.

The previous prime is 128728349. The next prime is 128728423. The reversal of 128728401 is 104827821.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-128728401 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (128728451) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 195010 + ... + 195668.

It is an arithmetic number, because the mean of its divisors is an integer number (5940000).

Almost surely, 2^128728401 is an apocalyptic number.

It is an amenable number.

128728401 is a deficient number, since it is larger than the sum of its proper divisors (61351599).

128728401 is a wasteful number, since it uses less digits than its factorization.

128728401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 853.

The product of its (nonzero) digits is 7168, while the sum is 33.

The square root of 128728401 is about 11345.8539123329. The cubic root of 128728401 is about 504.9225787269.

The spelling of 128728401 in words is "one hundred twenty-eight million, seven hundred twenty-eight thousand, four hundred one".