6688220 has 96 divisors (see below), whose sum is σ = 18095616. Its totient is φ = 2016000.

The previous prime is 6688217. The next prime is 6688267. The reversal of 6688220 is 228866.

It is a happy number.

It is an Ulam number.

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, 66170 + ... + 66270.

It is an arithmetic number, because the mean of its divisors is an integer number (188496).

Almost surely, 2^6688220 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 6688220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9047808).

6688220 is an abundant number, since it is smaller than the sum of its proper divisors (11407396).

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

6688220 is a wasteful number, since it uses less digits than its factorization.

6688220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 6688220 is about 2586.1593145048. The cubic root of 6688220 is about 188.4098122227.

It can be divided in two parts, 668 and 8220, that added together give a palindrome (8888).

The spelling of 6688220 in words is "six million, six hundred eighty-eight thousand, two hundred twenty".