6640448 has 28 divisors (see below), whose sum is σ = 13606272. Its totient is φ = 3212160.

The previous prime is 6640441. The next prime is 6640451. The reversal of 6640448 is 8440466.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311 + ... + 3657.

Almost surely, 2^6640448 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 6640448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6803136).

6640448 is an abundant number, since it is smaller than the sum of its proper divisors (6965824).

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

6640448 is a wasteful number, since it uses less digits than its factorization.

6640448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3390 (or 3380 counting only the distinct ones).

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

The square root of 6640448 is about 2576.9066727377. The cubic root of 6640448 is about 187.9601545253.

The spelling of 6640448 in words is "six million, six hundred forty thousand, four hundred forty-eight".