6640443 has 12 divisors (see below), whose sum is σ = 10096840. Its totient is φ = 4193856.

The previous prime is 6640441. The next prime is 6640451. The reversal of 6640443 is 3440466.

It is a happy number.

It is not a de Polignac number, because 6640443 - 2¹ = 6640441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6640441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19246 + ... + 19587.

Almost surely, 2^6640443 is an apocalyptic number.

6640443 is a deficient number, since it is larger than the sum of its proper divisors (3456397).

6640443 is a wasteful number, since it uses less digits than its factorization.

6640443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38858 (or 38855 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 6640443 is about 2576.9057025821. The cubic root of 6640443 is about 187.9601073497.

The spelling of 6640443 in words is "six million, six hundred forty thousand, four hundred forty-three".