128804009 has 4 divisors (see below), whose sum is σ = 128841216. Its totient is φ = 128766804.

The previous prime is 128804003. The next prime is 128804023. The reversal of 128804009 is 900408821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 900408821 = 13 ⋅69262217.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128804009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128804003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12809 + ... + 20534.

It is an arithmetic number, because the mean of its divisors is an integer number (32210304).

Almost surely, 2^128804009 is an apocalyptic number.

It is an amenable number.

128804009 is a deficient number, since it is larger than the sum of its proper divisors (37207).

128804009 is an equidigital number, since it uses as much as digits as its factorization.

128804009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37206.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 128804009 is about 11349.1853892691. The cubic root of 128804009 is about 505.0214139859.

The spelling of 128804009 in words is "one hundred twenty-eight million, eight hundred four thousand, nine".