6684385 has 4 divisors (see below), whose sum is σ = 8021268. Its totient is φ = 5347504.

The previous prime is 6684373. The next prime is 6684443. The reversal of 6684385 is 5834866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5834866 = 2 ⋅2917433.

It can be written as a sum of positive squares in 2 ways, for example, as 725904 + 5958481 = 852^2 + 2441^2 .

It is a cyclic number.

It is not a de Polignac number, because 6684385 - 2¹¹ = 6682337 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 668434 + ... + 668443.

It is an arithmetic number, because the mean of its divisors is an integer number (2005317).

Almost surely, 2^6684385 is an apocalyptic number.

It is an amenable number.

6684385 is a deficient number, since it is larger than the sum of its proper divisors (1336883).

6684385 is a wasteful number, since it uses less digits than its factorization.

6684385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336882.

The product of its digits is 138240, while the sum is 40.

The square root of 6684385 is about 2585.4177612138. The cubic root of 6684385 is about 188.3737941802.

The spelling of 6684385 in words is "six million, six hundred eighty-four thousand, three hundred eighty-five".