6720 has 56 divisors (see below), whose sum is σ = 24384. Its totient is φ = 1536.

The previous prime is 6719. The next prime is 6733. The reversal of 6720 is 276.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 6720.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 957 + ... + 963.

2⁶⁷²⁰ is an apocalyptic number.

6720 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 6720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12192).

6720 is an abundant number, since it is smaller than the sum of its proper divisors (17664).

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

6720 is a wasteful number, since it uses less digits than its factorization.

6720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 15.

The square root of 6720 is about 81.9756061277. The cubic root of 6720 is about 18.8707759213.

Adding to 6720 its reverse (276), we get a palindrome (6996).

The spelling of 6720 in words is "six thousand, seven hundred twenty".