Number of the day: 2017

Happy New Year!

Properties of the number 2017:

2017 is the 306^th prime.
2017 has 9 antidivisors and 2016 totatives.
2017 has a semiprime digit sum 10 in base 10.
2017 has a triangular digit sum 10 in base 10.
2017 has sum of divisors equal to 2018 which is an emirpimes.
Reversing the decimal digits of 2017 results in a sphenic number.
2017 = 1009² - 1008² is the difference of 2 nonnegative squares in 1 way.
2017 is the sum of 2 positive triangular numbers.
2017 is the difference of 2 positive pentagonal numbers in 1 way.
2017 = 9² + 44² is the sum of 2 positive squares in 1 way.
2017 = 21² + 26² + 30² is the sum of 3 positive squares.
2017² = 792² + 1855² is the sum of 2 positive squares in 1 way.
2017² is the sum of 3 positive squares.
2017 is a divisor of 229⁴ - 1.
2017 is an emirp in (at least) the following bases: 2, 3, 4, 7, 8, 9, 12, 16, 17, 19, 25, 33, 34, 37, 38, 45, 47, 49, 53, 54, 57, 59, 61, 64, 67, 68, 71, 74, 75, 77, 79, 83, 89, 92, 95, and 97.
2017 is palindromic in (at least) the following bases: 31, 32, 36, 42, -8, -48, -56, -63, -72, -84, and -96.
2017 in base 30 = 277 and consists of only the digits '2' and '7'.
2017 in base 31 = 232 and consists of only the digits '2' and '3'.
2017 in base 32 = 1v1 and consists of only the digits '1' and 'v'.
2017 in base 35 = 1mm and consists of only the digits '1' and 'm'.
2017 in base 36 = 1k1 and consists of only the digits '1' and 'k'.
2017 in base 41 = 188 and consists of only the digits '1' and '8'.
2017 in base 42 = 161 and consists of only the digits '1' and '6'.
2017 in base 44 = 11b and consists of only the digits '1' and 'b'.

The number 2017 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A005108: Class 4+ primes (for definition see A005105).
A005383: Numbers n such that both n and (n+1)/2 are primes.
A028916: Friedlander-Iwaniec primes: Primes of form a^2 + b^4.
A033215: Primes of form x^2+21*y^2.
A049774: Number of permutations of n elements not containing the consecutive pattern 123.
A107008: Primes of the form x^2+24*y^2.
A142006: Primes congruent to 2 mod 31.
A212959: Number of (w,x,y) such that w,x,y are all in {0,...,n} and |w-x|=|x-y|.
A235394: Primes whose decimal representation is a valid number in base 8 and interpreted as such is again a prime.
A242784: Number A(n,k) of permutations of [n] avoiding the consecutive step pattern given by the binary expansion of k, where 1=up and 0=down; square array A(n,k), n>=0, k>=0, read by antidiagonals.