20320 has 24 divisors (see below), whose sum is σ = 48384. Its totient is φ = 8064.

The previous prime is 20297. The next prime is 20323. The reversal of 20320 is 2302.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20323) by changing a digit.

20320 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 3 ways as a sum of consecutive naturals, for example, 97 + ... + 223.

It is an arithmetic number, because the mean of its divisors is an integer number (2016).

2²⁰³²⁰ is an apocalyptic number.

20320 is a gapful number since it is divisible by the number (20) 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 20320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24192).

20320 is an abundant number, since it is smaller than the sum of its proper divisors (28064).

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

20320 is a wasteful number, since it uses less digits than its factorization.

20320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 7.

The square root of 20320 is about 142.5482374496. The cubic root of 20320 is about 27.2881797953.

Adding to 20320 its reverse (2302), we get a palindrome (22622).

It can be divided in two parts, 20 and 320, that multiplied together give a square (6400 = 80²).

The spelling of 20320 in words is "twenty thousand, three hundred twenty", and thus it is an iban number.