20317 has 4 divisors (see below), whose sum is σ = 22176. Its totient is φ = 18460.

The previous prime is 20297. The next prime is 20323. The reversal of 20317 is 71302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20317 - 2¹¹ = 18269 is a prime.

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 20297 and 20306.

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 20317.

It is not an unprimeable number, because it can be changed into a prime (20327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 913 + ... + 934.

It is an arithmetic number, because the mean of its divisors is an integer number (5544).

2²⁰³¹⁷ is an apocalyptic number.

It is an amenable number.

20317 is a deficient number, since it is larger than the sum of its proper divisors (1859).

20317 is a wasteful number, since it uses less digits than its factorization.

20317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1858.

The product of its (nonzero) digits is 42, while the sum is 13.

The square root of 20317 is about 142.5377143075. The cubic root of 20317 is about 27.2868368069.

Adding to 20317 its reverse (71302), we get a palindrome (91619).

The spelling of 20317 in words is "twenty thousand, three hundred seventeen", and thus it is an iban number.