20835 has 12 divisors (see below), whose sum is σ = 36192. Its totient is φ = 11088.

The previous prime is 20809. The next prime is 20849. The reversal of 20835 is 53802.

It is not a de Polignac number, because 20835 - 2⁶ = 20771 is a prime.

20835 is a lucky number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 187 + ... + 276.

It is an arithmetic number, because the mean of its divisors is an integer number (3016).

2²⁰⁸³⁵ is an apocalyptic number.

20835 is a deficient number, since it is larger than the sum of its proper divisors (15357).

20835 is a wasteful number, since it uses less digits than its factorization.

20835 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 20835 is about 144.3433406846. The cubic root of 20835 is about 27.5167941495.

It can be divided in two parts, 208 and 35, that added together give a 5-th power (243 = 3⁵).

The spelling of 20835 in words is "twenty thousand, eight hundred thirty-five".