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
551 991 8
552 996 8
553 1008 8
554 1020 8
555 1033 8
556 1071 8
557 1080 8
558 1088 8
559 1092 8
560 1093 8
561 1113 8
562 1123 8
563 1131 8
564 1160 8
565 1163 8
566 1171 8
567 1192 8
568 1197 8
569 1248 8
570 1249 8
571 1250 8
572 1256 8
573 1259 8
574 1275 8
575 1300 8
576 1311 8
577 1312 8
578 1327 8
579 1336 8
580 1352 8
581 1356 8
582 1364 8
583 1372 8
584 1376 8
585 1384 8
586 1399 8
587 1423 8
588 1431 8
589 1432 8
590 1449 8
591 1459 8
592 1471 8
593 1531 8
594 1543 8
595 1544 8
596 1550 8
597 1560 8
598 1567 8
599 1568 8
600 1571 8