13820 has 12 divisors (see below), whose sum is σ = 29064. Its totient is φ = 5520.

The previous prime is 13807. The next prime is 13829. The reversal of 13820 is 2831.

13820 = 38² + 39² + ... + 45².

It is a junction number, because it is equal to n+sod(n) for n = 13795 and 13804.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 13820.

It is not an unprimeable number, because it can be changed into a prime (13829) by changing a digit.

13820 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, 326 + ... + 365.

It is an arithmetic number, because the mean of its divisors is an integer number (2422).

13820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13820 is an abundant number, since it is smaller than the sum of its proper divisors (15244).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14532).

13820 is a wasteful number, since it uses less digits than its factorization.

13820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700 (or 698 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 13820 is about 117.5584960775. The cubic root of 13820 is about 23.9976849619.

The spelling of 13820 in words is "thirteen thousand, eight hundred twenty".