6684640 has 48 divisors (see below), whose sum is σ = 16193520. Its totient is φ = 2606080.

The previous prime is 6684631. The next prime is 6684647. The reversal of 6684640 is 464866.

It is a junction number, because it is equal to n+sod(n) for n = 6684596 and 6684605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6684647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6051 + ... + 7069.

It is an arithmetic number, because the mean of its divisors is an integer number (337365).

Almost surely, 2^6684640 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 6684640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8096760).

6684640 is an abundant number, since it is smaller than the sum of its proper divisors (9508880).

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

6684640 is a wasteful number, since it uses less digits than its factorization.

6684640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1075 (or 1067 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 6684640 is about 2585.4670757911. The cubic root of 6684640 is about 188.3761895492.

The spelling of 6684640 in words is "six million, six hundred eighty-four thousand, six hundred forty".