6688 has 24 divisors (see below), whose sum is σ = 15120. Its totient is φ = 2880.

The previous prime is 6679. The next prime is 6689. The reversal of 6688 is 8866.

Its product of digits (2304) is a multiple of the sum of its prime divisors (32).

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (6689) by changing a digit.

6688 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 343 + ... + 361.

It is an arithmetic number, because the mean of its divisors is an integer number (630).

2⁶⁶⁸⁸ 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 6688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7560).

6688 is an abundant number, since it is smaller than the sum of its proper divisors (8432).

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

6688 is a wasteful number, since it uses less digits than its factorization.

6688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40 (or 32 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 6688 is about 81.7801932010. The cubic root of 6688 is about 18.8407746371.

It can be divided in two parts, 668 and 8, that added together give a palindrome (676).

The spelling of 6688 in words is "six thousand, six hundred eighty-eight".