6628440 has 128 divisors (see below), whose sum is σ = 24514560. Its totient is φ = 1396224.

The previous prime is 6628423. The next prime is 6628477. The reversal of 6628440 is 448266.

6628440 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 6628398 and 6628407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10617 + ... + 11223.

It is an arithmetic number, because the mean of its divisors is an integer number (191520).

Almost surely, 2^6628440 is an apocalyptic number.

6628440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6628440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12257280).

6628440 is an abundant number, since it is smaller than the sum of its proper divisors (17886120).

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

6628440 is a wasteful number, since it uses less digits than its factorization.

6628440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641 (or 637 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 6628440 is about 2574.5756931968. The cubic root of 6628440 is about 187.8467893139.

The spelling of 6628440 in words is "six million, six hundred twenty-eight thousand, four hundred forty".