128409591 has 8 divisors (see below), whose sum is σ = 171282304. Its totient is φ = 85571640.

The previous prime is 128409583. The next prime is 128409623. The reversal of 128409591 is 195904821.

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

It is not a de Polignac number, because 128409591 - 2³ = 128409583 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 (128409511) 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, 1710 + ... + 16116.

It is an arithmetic number, because the mean of its divisors is an integer number (21410288).

Almost surely, 2^128409591 is an apocalyptic number.

128409591 is a deficient number, since it is larger than the sum of its proper divisors (42872713).

128409591 is a wasteful number, since it uses less digits than its factorization.

128409591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17381.

The product of its (nonzero) digits is 25920, while the sum is 39.

The square root of 128409591 is about 11331.7955770478. The cubic root of 128409591 is about 504.5054020991.

The spelling of 128409591 in words is "one hundred twenty-eight million, four hundred nine thousand, five hundred ninety-one".