6639968 has 48 divisors (see below), whose sum is σ = 14051520. Its totient is φ = 3079296.

The previous prime is 6639943. The next prime is 6639989. The reversal of 6639968 is 8699366.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40655 + ... + 40817.

It is an arithmetic number, because the mean of its divisors is an integer number (292740).

Almost surely, 2^6639968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6639968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7025760).

6639968 is an abundant number, since it is smaller than the sum of its proper divisors (7411552).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6639968 is a wasteful number, since it uses less digits than its factorization.

6639968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259 (or 251 counting only the distinct ones).

The product of its digits is 419904, while the sum is 47.

The square root of 6639968 is about 2576.8135361333. The cubic root of 6639968 is about 187.9556255613.

The spelling of 6639968 in words is "six million, six hundred thirty-nine thousand, nine hundred sixty-eight".