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
451 1692 9
452 1699 9
453 1708 9
454 1723 9
455 1733 9
456 1752 9
457 1755 9
458 1784 9
459 1787 9
460 1840 9
461 1847 9
462 1871 9
463 1872 9
464 1879 9
465 1901 9
466 1951 9
467 1956 9
468 1999 9
469 13 8
470 20 8
471 30 8
472 44 8
473 53 8
474 54 8
475 57 8
476 66 8
477 67 8
478 69 8
479 70 8
480 91 8
481 109 8
482 113 8
483 115 8
484 133 8
485 163 8
486 171 8
487 173 8
488 176 8
489 177 8
490 184 8
491 192 8
492 211 8
493 223 8
494 231 8
495 234 8
496 249 8
497 250 8
498 296 8
499 300 8
500 313 8