20560 has 20 divisors (see below), whose sum is σ = 47988. Its totient is φ = 8192.

The previous prime is 20551. The next prime is 20563. The reversal of 20560 is 6502.

20560 = T₂₁ + T₂₂ + ... + T₅₀.

20560 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 15376 + 5184 = 124^2 + 72^2 .

It is a tau number, because it is divible by the number of its divisors (20).

20560 is an undulating number in base 16.

20560 is strictly pandigital in base 6.

It is a nialpdrome in base 12.

It is a zygodrome in base 4.

It is a self number, because there is not a number n which added to its sum of digits gives 20560.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20563) by changing a digit.

In principle, a polygon with 20560 sides can be constructed with ruler and compass.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 49 + ... + 208.

2²⁰⁵⁶⁰ is an apocalyptic number.

20560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20560 is an abundant number, since it is smaller than the sum of its proper divisors (27428).

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 (23994).

20560 is a wasteful number, since it uses less digits than its factorization.

20560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 270 (or 264 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 20560 is about 143.3875866315. The cubic root of 20560 is about 27.3951933601.

The spelling of 20560 in words is "twenty thousand, five hundred sixty".