20356 has 12 divisors (see below), whose sum is σ = 40768. Its totient is φ = 8712.

The previous prime is 20353. The next prime is 20357. The reversal of 20356 is 65302.

20356 is an admirable number.

It is a d-powerful number, because it can be written as 2⁹ + 0 + 3⁹ + 5³ + 6² .

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (20353) by changing a digit.

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, 336 + ... + 391.

2²⁰³⁵⁶ is an apocalyptic number.

It is an amenable number.

20356 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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 (20384).

20356 is a wasteful number, since it uses less digits than its factorization.

20356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 738 (or 736 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 16.

The square root of 20356 is about 142.6744546161. The cubic root of 20356 is about 27.3042853546.

Adding to 20356 its reverse (65302), we get a palindrome (85658).

The spelling of 20356 in words is "twenty thousand, three hundred fifty-six".