6639843 has 24 divisors (see below), whose sum is σ = 10908432. Its totient is φ = 3569664.

The previous prime is 6639839. The next prime is 6639851. The reversal of 6639843 is 3489366.

It is not a de Polignac number, because 6639843 - 2² = 6639839 is a prime.

It is a d-powerful number, because it can be written as 6 + 6⁸ + 3¹¹ + 9² + 8 + 4² + 3¹⁴ .

It is not an unprimeable number, because it can be changed into a prime (6639803) 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 23 ways as a sum of consecutive naturals, for example, 1171 + ... + 3827.

It is an arithmetic number, because the mean of its divisors is an integer number (454518).

Almost surely, 2^6639843 is an apocalyptic number.

6639843 is a deficient number, since it is larger than the sum of its proper divisors (4268589).

6639843 is a wasteful number, since it uses less digits than its factorization.

6639843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2691 (or 2684 counting only the distinct ones).

The product of its digits is 93312, while the sum is 39.

The square root of 6639843 is about 2576.7892812568. The cubic root of 6639843 is about 187.9544461078.

The spelling of 6639843 in words is "six million, six hundred thirty-nine thousand, eight hundred forty-three".