128809506 has 32 divisors (see below), whose sum is σ = 302382720. Its totient is φ = 35807616.

The previous prime is 128809487. The next prime is 128809511. The reversal of 128809506 is 605908821.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39891 + ... + 42998.

It is an arithmetic number, because the mean of its divisors is an integer number (9449460).

Almost surely, 2^128809506 is an apocalyptic number.

128809506 is an abundant number, since it is smaller than the sum of its proper divisors (173573214).

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

128809506 is a wasteful number, since it uses less digits than its factorization.

128809506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82938.

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 128809506 is about 11349.4275626571. The cubic root of 128809506 is about 505.0285981909.

The spelling of 128809506 in words is "one hundred twenty-eight million, eight hundred nine thousand, five hundred six".