Interestingness score

How we rank numbers on NumDic

How it’s calculated

Each number gets a score from the properties shown on its page (number-theory characteristics and base-10 digit properties):

  • Base: +1 point for every property chip (e.g. Prime, Triangular, Palindromic).
  • Bonus (rare): +3 for very special properties: Mersenne, Mersenne prime, Fermat number, Catalan number, Dudeney number, Perfect, Narcissistic.
  • Bonus (medium): +2 for other notable ones: Sophie Germain prime, Safe prime, Layland, Factorial, Pandigital, Strobogrammatic, Refactorable, Powerful number, Lucas number, Gaussian prime, Kaprekar, Smith, Automorphic, Trimorphic, Hoax number, Zuckerman number.

The total is the interestingness score. Higher means more properties and/or rarer ones. On each number page you also see how many chips are in each section.

Example

Number 6 has a score of 31.

It has the following properties (each contributing base points and possibly bonus):

Triangular, Hexagonal, Evil number, Pronic, Factorial, Even, Ones-Zeroes, Palindromic, Harshad, Repdigit, Automorphic, Spy number, Narcissistic, Trimorphic, Zuckerman number, Composite, Perfect

Plus the usual classification (Prime/Unit/Composite) and, when applicable, Perfect/Abundant/Deficient and Twin Prime.

Top 1000 most interesting numbers

Precomputed list; same order as on number pages (by score, then by number). Paginated 50 per page.

Rank Number Score
201 948 11
202 983 11
203 985 11
204 1001 11
205 1016 11
206 1023 11
207 1056 11
208 1086 11
209 1165 11
210 1187 11
211 1219 11
212 1223 11
213 1255 11
214 1260 11
215 1283 11
216 1284 11
217 1303 11
218 1331 11
219 1367 11
220 1404 11
221 1444 11
222 1499 11
223 1520 11
224 1523 11
225 1559 11
226 1576 11
227 1583 11
228 1607 11
229 1633 11
230 1680 11
231 1728 11
232 1764 11
233 1795 11
234 1811 11
235 1823 11
236 1824 11
237 1921 11
238 1980 11
239 10 10
240 19 10
241 21 10
242 56 10
243 58 10
244 80 10
245 139 10
246 151 10
247 156 10
248 166 10
249 169 10
250 180 10