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
251 181 10
252 196 10
253 200 10
254 224 10
255 232 10
256 255 10
257 274 10
258 276 10
259 289 10
260 308 10
261 312 10
262 346 10
263 360 10
264 378 10
265 382 10
266 392 10
267 396 10
268 438 10
269 448 10
270 500 10
271 526 10
272 529 10
273 560 10
274 562 10
275 634 10
276 640 10
277 644 10
278 654 10
279 660 10
280 702 10
281 762 10
282 778 10
283 800 10
284 804 10
285 809 10
286 828 10
287 841 10
288 860 10
289 880 10
290 904 10
291 907 10
292 922 10
293 936 10
294 958 10
295 961 10
296 1039 10
297 1040 10
298 1044 10
299 1049 10
300 1051 10