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
851 309 6
852 310 6
853 321 6
854 323 6
855 329 6
856 340 6
857 349 6
858 353 6
859 356 6
860 363 6
861 365 6
862 373 6
863 377 6
864 393 6
865 397 6
866 399 6
867 401 6
868 402 6
869 406 6
870 410 6
871 414 6
872 421 6
873 423 6
874 425 6
875 433 6
876 451 6
877 461 6
878 474 6
879 477 6
880 490 6
881 507 6
882 513 6
883 515 6
884 520 6
885 525 6
886 528 6
887 531 6
888 532 6
889 545 6
890 550 6
891 556 6
892 559 6
893 569 6
894 575 6
895 580 6
896 585 6
897 590 6
898 592 6
899 604 6
900 606 6