128919109 has 16 divisors (see below), whose sum is σ = 149333760. Its totient is φ = 109992960.

The previous prime is 128919103. The next prime is 128919113. The reversal of 128919109 is 901919821.

It is not a de Polignac number, because 128919109 - 2⁹ = 128918597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128919103) 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, 85837 + ... + 87325.

It is an arithmetic number, because the mean of its divisors is an integer number (9333360).

Almost surely, 2^128919109 is an apocalyptic number.

It is an amenable number.

128919109 is a deficient number, since it is larger than the sum of its proper divisors (20414651).

128919109 is a wasteful number, since it uses less digits than its factorization.

128919109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1980.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 128919109 is about 11354.2551054660. The cubic root of 128919109 is about 505.1717992089.

The spelling of 128919109 in words is "one hundred twenty-eight million, nine hundred nineteen thousand, one hundred nine".