6628644 has 72 divisors (see below), whose sum is σ = 19262880. Its totient is φ = 1900800.

The previous prime is 6628639. The next prime is 6628651. The reversal of 6628644 is 4468266.

It is a happy number.

6628644 is a `hidden beast` number, since 6 + 6 + 2 + 8 + 644 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 6628599 and 6628608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7084 + ... + 7964.

It is an arithmetic number, because the mean of its divisors is an integer number (267540).

Almost surely, 2^6628644 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 6628644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9631440).

6628644 is an abundant number, since it is smaller than the sum of its proper divisors (12634236).

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

6628644 is a wasteful number, since it uses less digits than its factorization.

6628644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 921 (or 916 counting only the distinct ones).

The product of its digits is 55296, while the sum is 36.

The square root of 6628644 is about 2574.6153110708. The cubic root of 6628644 is about 187.8487163813.

The spelling of 6628644 in words is "six million, six hundred twenty-eight thousand, six hundred forty-four".