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
651	193	7
652	201	7
653	203	7
654	207	7
655	208	7
656	209	7
657	220	7
658	222	7
659	230	7
660	247	7
661	261	7
662	272	7
663	301	7
664	303	7
665	306	7
666	330	7
667	341	7
668	342	7
669	351	7
670	380	7
671	403	7
672	405	7
673	409	7
674	435	7
675	460	7
676	464	7
677	465	7
678	469	7
679	481	7
680	505	7
681	506	7
682	508	7
683	510	7
684	552	7
685	561	7
686	565	7
687	595	7
688	601	7
689	603	7
690	605	7
691	608	7
692	616	7
693	617	7
694	637	7
695	651	7
696	656	7
697	680	7
698	704	7
699	707	7
700	709	7

Back to home

Rank	Number	Score
651	193	7
652	201	7
653	203	7
654	207	7
655	208	7
656	209	7
657	220	7
658	222	7
659	230	7
660	247	7
661	261	7
662	272	7
663	301	7
664	303	7
665	306	7
666	330	7
667	341	7
668	342	7
669	351	7
670	380	7
671	403	7
672	405	7
673	409	7
674	435	7
675	460	7
676	464	7
677	465	7
678	469	7
679	481	7
680	505	7
681	506	7
682	508	7
683	510	7
684	552	7
685	561	7
686	565	7
687	595	7
688	601	7
689	603	7
690	605	7
691	608	7
692	616	7
693	617	7
694	637	7
695	651	7
696	656	7
697	680	7
698	704	7
699	707	7
700	709	7

Rank	Number	Score
651	193	7
652	201	7
653	203	7
654	207	7
655	208	7
656	209	7
657	220	7
658	222	7
659	230	7
660	247	7
661	261	7
662	272	7
663	301	7
664	303	7
665	306	7
666	330	7
667	341	7
668	342	7
669	351	7
670	380	7
671	403	7
672	405	7
673	409	7
674	435	7
675	460	7
676	464	7
677	465	7
678	469	7
679	481	7
680	505	7
681	506	7
682	508	7
683	510	7
684	552	7
685	561	7
686	565	7
687	595	7
688	601	7
689	603	7
690	605	7
691	608	7
692	616	7
693	617	7
694	637	7
695	651	7
696	656	7
697	680	7
698	704	7
699	707	7
700	709	7

Rank	Number	Score
651	193	7
652	201	7
653	203	7
654	207	7
655	208	7
656	209	7
657	220	7
658	222	7
659	230	7
660	247	7
661	261	7
662	272	7
663	301	7
664	303	7
665	306	7
666	330	7
667	341	7
668	342	7
669	351	7
670	380	7
671	403	7
672	405	7
673	409	7
674	435	7
675	460	7
676	464	7
677	465	7
678	469	7
679	481	7
680	505	7
681	506	7
682	508	7
683	510	7
684	552	7
685	561	7
686	565	7
687	595	7
688	601	7
689	603	7
690	605	7
691	608	7
692	616	7
693	617	7
694	637	7
695	651	7
696	656	7
697	680	7
698	704	7
699	707	7
700	709	7