128611109 has 8 divisors (see below), whose sum is σ = 140395680. Its totient is φ = 116842000.

The previous prime is 128611081. The next prime is 128611121. The reversal of 128611109 is 901116821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128611109 - 2¹² = 128607013 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 (128611159) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19934 + ... + 25584.

It is an arithmetic number, because the mean of its divisors is an integer number (17549460).

Almost surely, 2^128611109 is an apocalyptic number.

It is an amenable number.

128611109 is a deficient number, since it is larger than the sum of its proper divisors (11784571).

128611109 is a wasteful number, since it uses less digits than its factorization.

128611109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7731.

The product of its (nonzero) digits is 864, while the sum is 29.

The square root of 128611109 is about 11340.6837977258. The cubic root of 128611109 is about 504.7691772629.

The spelling of 128611109 in words is "one hundred twenty-eight million, six hundred eleven thousand, one hundred nine".