20568 has 16 divisors (see below), whose sum is σ = 51480. Its totient is φ = 6848.

The previous prime is 20563. The next prime is 20593. The reversal of 20568 is 86502.

It is a happy number.

It is a nialpdrome in base 12.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 405 + ... + 452.

2²⁰⁵⁶⁸ is an apocalyptic number.

It is an amenable number.

20568 is an abundant number, since it is smaller than the sum of its proper divisors (30912).

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 (25740).

20568 is a wasteful number, since it uses less digits than its factorization.

20568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 866 (or 862 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 20568 is about 143.4154803360. The cubic root of 20568 is about 27.3987461021.

The spelling of 20568 in words is "twenty thousand, five hundred sixty-eight".