20256 has 24 divisors (see below), whose sum is σ = 53424. Its totient is φ = 6720.

The previous prime is 20249. The next prime is 20261. The reversal of 20256 is 65202.

20256 is nontrivially palindromic in base 15.

It is a tau number, because it is divible by the number of its divisors (24).

It is a nialpdrome in base 12.

It is an unprimeable number.

20256 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, 10 + ... + 201.

It is an arithmetic number, because the mean of its divisors is an integer number (2226).

2²⁰²⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26712).

20256 is an abundant number, since it is smaller than the sum of its proper divisors (33168).

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

20256 is a wasteful number, since it uses less digits than its factorization.

20256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224 (or 216 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 20256 is about 142.3235749973. The cubic root of 20256 is about 27.2595006572.

Adding to 20256 its reverse (65202), we get a palindrome (85458).

It can be divided in two parts, 20 and 256, that added together give a triangular number (276 = T₂₃).

The spelling of 20256 in words is "twenty thousand, two hundred fifty-six".