128331009 has 24 divisors (see below), whose sum is σ = 192022272. Its totient is φ = 82535040.

The previous prime is 128331001. The next prime is 128331019. The reversal of 128331009 is 900133821.

It is not a de Polignac number, because 128331009 - 2³ = 128331001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128331001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27897 + ... + 32169.

It is an arithmetic number, because the mean of its divisors is an integer number (8000928).

Almost surely, 2^128331009 is an apocalyptic number.

It is an amenable number.

128331009 is a deficient number, since it is larger than the sum of its proper divisors (63691263).

128331009 is a wasteful number, since it uses less digits than its factorization.

128331009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4397 (or 4394 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 128331009 is about 11328.3277230137. The cubic root of 128331009 is about 504.4024681125.

The spelling of 128331009 in words is "one hundred twenty-eight million, three hundred thirty-one thousand, nine".