6688409 has 16 divisors (see below), whose sum is σ = 8362368. Its totient is φ = 5208192.

The previous prime is 6688393. The next prime is 6688411. The reversal of 6688409 is 9048866.

It is a cyclic number.

It is not a de Polignac number, because 6688409 - 2⁴ = 6688393 is a prime.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (6688499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5549 + ... + 6645.

It is an arithmetic number, because the mean of its divisors is an integer number (522648).

Almost surely, 2^6688409 is an apocalyptic number.

It is an amenable number.

6688409 is a deficient number, since it is larger than the sum of its proper divisors (1673959).

6688409 is a wasteful number, since it uses less digits than its factorization.

6688409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1184.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 6688409 is about 2586.1958549190. The cubic root of 6688409 is about 188.4115869410.

The spelling of 6688409 in words is "six million, six hundred eighty-eight thousand, four hundred nine".