6660 has 36 divisors (see below), whose sum is σ = 20748.
Its totient is φ = 1728.
The previous prime is 6659. The next prime is 6661. The reversal of 6660 is 666.
6660 is nontrivially palindromic in base 11.
It is an interprime number because it is at equal distance from previous prime (6659) and next prime (6661).
It can be written as a sum of positive squares in 2 ways, for example, as 4356 + 2304 = 66^2 + 48^2
It is a tau number, because it is divible by the number of its divisors (36).
It is a Harshad number since it is a multiple of its sum of digits (18).
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a nialpdrome in base 10.
It is not an unprimeable number, because it can be changed into a prime (6661) by changing a digit.
It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 162 + ... + 198.
6660 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 6660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10374).
6660 is an abundant number, since it is smaller than the sum of its proper divisors (14088).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
6660 is a wasteful number, since it uses less digits than its factorization.
6660 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 52 (or 47 counting only the distinct ones).
The product of its (nonzero) digits is 216, while the sum is 18.
The square root of 6660 is about 81.6088230524.
The cubic root of 6660 is about 18.8144449117.
It can be divided in two parts, 6 and 660, that added together give a palindrome (666).
The spelling of 6660 in words is "six thousand, six hundred sixty".