13720 has 32 divisors (see below), whose sum is σ = 36000. Its totient is φ = 4704.

The previous prime is 13711. The next prime is 13721. The reversal of 13720 is 2731.

13720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nialpdrome in base 7 and base 14.

It is a zygodrome in base 7.

It is a self number, because there is not a number n which added to its sum of digits gives 13720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13721) by changing a digit.

13720 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1957 + ... + 1963.

It is an arithmetic number, because the mean of its divisors is an integer number (1125).

2¹³⁷²⁰ is an apocalyptic number.

13720 is a gapful number since it is divisible by the number (10) 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 13720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18000).

13720 is an abundant number, since it is smaller than the sum of its proper divisors (22280).

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

13720 is an equidigital number, since it uses as much as digits as its factorization.

13720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32 (or 14 counting only the distinct ones).

The product of its (nonzero) digits is 42, while the sum is 13.

The square root of 13720 is about 117.1324037148. The cubic root of 13720 is about 23.9396632535.

It can be divided in two parts, 1 and 3720, that added together give a square (3721 = 61²).

The spelling of 13720 in words is "thirteen thousand, seven hundred twenty".