6663440 has 80 divisors (see below), whose sum is σ = 18058368. Its totient is φ = 2239488.

The previous prime is 6663431. The next prime is 6663451. The reversal of 6663440 is 443666.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40799 + ... + 40961.

Almost surely, 2^6663440 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 6663440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9029184).

6663440 is an abundant number, since it is smaller than the sum of its proper divisors (11394928).

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

6663440 is a wasteful number, since it uses less digits than its factorization.

6663440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 250 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 29.

The square root of 6663440 is about 2581.3639805343. The cubic root of 6663440 is about 188.1768367803.

The spelling of 6663440 in words is "six million, six hundred sixty-three thousand, four hundred forty".