6439909 has 16 divisors (see below), whose sum is σ = 7741440. Its totient is φ = 5240880.

The previous prime is 6439903. The next prime is 6439919. The reversal of 6439909 is 9099346.

It is a cyclic number.

It is not a de Polignac number, because 6439909 - 2⁹ = 6439397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6439903) 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, 12552 + ... + 13054.

It is an arithmetic number, because the mean of its divisors is an integer number (483840).

Almost surely, 2^6439909 is an apocalyptic number.

It is an amenable number.

6439909 is a deficient number, since it is larger than the sum of its proper divisors (1301531).

6439909 is a wasteful number, since it uses less digits than its factorization.

6439909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 600.

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

The square root of 6439909 is about 2537.6975785148. The cubic root of 6439909 is about 186.0486730445.

The spelling of 6439909 in words is "six million, four hundred thirty-nine thousand, nine hundred nine".