8128409 has 8 divisors (see below), whose sum is σ = 8586240. Its totient is φ = 7673616.

The previous prime is 8128403. The next prime is 8128411. The reversal of 8128409 is 9048218.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 8128409 - 2²⁰ = 7079833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8128403) 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, 6719 + ... + 7835.

It is an arithmetic number, because the mean of its divisors is an integer number (1073280).

Almost surely, 2^8128409 is an apocalyptic number.

It is an amenable number.

8128409 is a deficient number, since it is larger than the sum of its proper divisors (457831).

8128409 is a wasteful number, since it uses less digits than its factorization.

8128409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1519.

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

The square root of 8128409 is about 2851.0364781953. The cubic root of 8128409 is about 201.0644002117.

The spelling of 8128409 in words is "eight million, one hundred twenty-eight thousand, four hundred nine".