128385209 has 4 divisors (see below), whose sum is σ = 128469120. Its totient is φ = 128301300.

The previous prime is 128385197. The next prime is 128385211. The reversal of 128385209 is 902583821.

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.

It is a cyclic number.

It is not a de Polignac number, because 128385209 - 2⁴ = 128385193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128385409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39617 + ... + 42734.

It is an arithmetic number, because the mean of its divisors is an integer number (32117280).

Almost surely, 2^128385209 is an apocalyptic number.

It is an amenable number.

128385209 is a deficient number, since it is larger than the sum of its proper divisors (83911).

128385209 is an equidigital number, since it uses as much as digits as its factorization.

128385209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83910.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 128385209 is about 11330.7197035316. The cubic root of 128385209 is about 504.4734687903.

The spelling of 128385209 in words is "one hundred twenty-eight million, three hundred eighty-five thousand, two hundred nine".