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
351 248 9
352 257 9
353 271 9
354 280 9
355 281 9
356 283 9
357 293 9
358 297 9
359 307 9
360 311 9
361 315 9
362 331 9
363 336 9
364 364 9
365 367 9
366 368 9
367 371 9
368 372 9
369 375 9
370 379 9
371 429 9
372 450 9
373 463 9
374 468 9
375 476 9
376 487 9
377 501 9
378 509 9
379 521 9
380 523 9
381 536 9
382 540 9
383 571 9
384 588 9
385 599 9
386 607 9
387 609 9
388 632 9
389 641 9
390 643 9
391 650 9
392 653 9
393 684 9
394 708 9
395 727 9
396 739 9
397 761 9
398 780 9
399 787 9
400 792 9