20855 has 8 divisors (see below), whose sum is σ = 25872. Its totient is φ = 16128.

The previous prime is 20849. The next prime is 20857. The reversal of 20855 is 55802.

20855 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20855 - 2⁸ = 20599 is a prime.

It is a Duffinian number.

20855 is strictly pandigital in base 6.

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 (20857) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 167 + ... + 263.

It is an arithmetic number, because the mean of its divisors is an integer number (3234).

2²⁰⁸⁵⁵ is an apocalyptic number.

20855 is a deficient number, since it is larger than the sum of its proper divisors (5017).

20855 is an equidigital number, since it uses as much as digits as its factorization.

20855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 20855 is about 144.4126033281. The cubic root of 20855 is about 27.5255960035.

The spelling of 20855 in words is "twenty thousand, eight hundred fifty-five".