6684440 has 32 divisors (see below), whose sum is σ = 17189280. Its totient is φ = 2291712.

The previous prime is 6684373. The next prime is 6684443. The reversal of 6684440 is 444866.

It is a super-2 number, since 2×6684440² = 89363476227200, which contains 22 as substring.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 6684397 and 6684406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6684443) 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, 11657 + ... + 12216.

It is an arithmetic number, because the mean of its divisors is an integer number (537165).

Almost surely, 2^6684440 is an apocalyptic number.

It is an amenable number.

6684440 is an abundant number, since it is smaller than the sum of its proper divisors (10504840).

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

6684440 is a wasteful number, since it uses less digits than its factorization.

6684440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23891 (or 23887 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The square root of 6684440 is about 2585.4283977709. The cubic root of 6684440 is about 188.3743108336.

The spelling of 6684440 in words is "six million, six hundred eighty-four thousand, four hundred forty".