6399409 has 8 divisors (see below), whose sum is σ = 6919040. Its totient is φ = 5898096.

The previous prime is 6399397. The next prime is 6399427. The reversal of 6399409 is 9049936.

6399409 is nontrivially palindromic in base 3.

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

It is not a de Polignac number, because 6399409 - 2⁵ = 6399377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6399109) 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 7 ways as a sum of consecutive naturals, for example, 3849 + ... + 5254.

It is an arithmetic number, because the mean of its divisors is an integer number (864880).

Almost surely, 2^6399409 is an apocalyptic number.

It is an amenable number.

6399409 is a deficient number, since it is larger than the sum of its proper divisors (519631).

6399409 is a wasteful number, since it uses less digits than its factorization.

6399409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9159.

The product of its (nonzero) digits is 52488, while the sum is 40.

The square root of 6399409 is about 2529.7053188069. The cubic root of 6399409 is about 185.6578382123.

The spelling of 6399409 in words is "six million, three hundred ninety-nine thousand, four hundred nine".