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
301 1063 10
302 1091 10
303 1125 10
304 1148 10
305 1151 10
306 1156 10
307 1200 10
308 1282 10
309 1304 10
310 1308 10
311 1323 10
312 1360 10
313 1369 10
314 1408 10
315 1427 10
316 1440 10
317 1481 10
318 1540 10
319 1620 10
320 1626 10
321 1642 10
322 1678 10
323 1681 10
324 1822 10
325 1842 10
326 1849 10
327 1858 10
328 1894 10
329 1936 10
330 1966 10
331 14 9
332 41 9
333 43 9
334 51 9
335 71 9
336 75 9
337 79 9
338 89 9
339 104 9
340 123 9
341 135 9
342 145 9
343 152 9
344 160 9
345 175 9
346 190 9
347 210 9
348 212 9
349 228 9
350 233 9