128089809 has 16 divisors (see below), whose sum is σ = 190045440. Its totient is φ = 85266000.

The previous prime is 128089789. The next prime is 128089823. The reversal of 128089809 is 908980821.

It is not a de Polignac number, because 128089809 - 2⁵ = 128089777 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128089859) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17119 + ... + 23435.

It is an arithmetic number, because the mean of its divisors is an integer number (11877840).

Almost surely, 2^128089809 is an apocalyptic number.

It is an amenable number.

128089809 is a deficient number, since it is larger than the sum of its proper divisors (61955631).

128089809 is an equidigital number, since it uses as much as digits as its factorization.

128089809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7077 (or 7071 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The square root of 128089809 is about 11317.6768375846. The cubic root of 128089809 is about 504.0862593289.

The spelling of 128089809 in words is "one hundred twenty-eight million, eighty-nine thousand, eight hundred nine".