20853 has 12 divisors (see below), whose sum is σ = 34528. Its totient is φ = 11880.

The previous prime is 20849. The next prime is 20857. The reversal of 20853 is 35802.

It is an interprime number because it is at equal distance from previous prime (20849) and next prime (20857).

It is not a de Polignac number, because 20853 - 2² = 20849 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20853.

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 11 ways as a sum of consecutive naturals, for example, 103 + ... + 228.

2²⁰⁸⁵³ is an apocalyptic number.

It is an amenable number.

20853 is a deficient number, since it is larger than the sum of its proper divisors (13675).

20853 is a wasteful number, since it uses less digits than its factorization.

20853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344 (or 341 counting only the distinct ones).

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

The square root of 20853 is about 144.4056785587. The cubic root of 20853 is about 27.5247160714.

The spelling of 20853 in words is "twenty thousand, eight hundred fifty-three".