6681 has 8 divisors (see below), whose sum is σ = 9504. Its totient is φ = 4160.

The previous prime is 6679. The next prime is 6689. The reversal of 6681 is 1866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6681 - 2¹ = 6679 is a prime.

It is a super-2 number, since 2×6681² = 89271522, which contains 22 as substring.

It is a congruent number.

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

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15 + ... + 116.

It is an arithmetic number, because the mean of its divisors is an integer number (1188).

2⁶⁶⁸¹ is an apocalyptic number.

It is an amenable number.

6681 is a deficient number, since it is larger than the sum of its proper divisors (2823).

6681 is a wasteful number, since it uses less digits than its factorization.

6681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151.

The product of its digits is 288, while the sum is 21.

The square root of 6681 is about 81.7373843477. The cubic root of 6681 is about 18.8341991057.

The spelling of 6681 in words is "six thousand, six hundred eighty-one".