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
151 1944 12
152 40 11
153 42 11
154 45 11
155 60 11
156 63 11
157 94 11
158 101 11
159 103 11
160 112 11
161 204 11
162 243 11
163 252 11
164 265 11
165 320 11
166 324 11
167 343 11
168 355 11
169 370 11
170 407 11
171 443 11
172 444 11
173 454 11
174 467 11
175 479 11
176 480 11
177 483 11
178 484 11
179 491 11
180 499 11
181 504 11
182 511 11
183 517 11
184 587 11
185 593 11
186 600 11
187 627 11
188 663 11
189 666 11
190 672 11
191 676 11
192 703 11
193 706 11
194 743 11
195 751 11
196 784 11
197 839 11
198 887 11
199 895 11
200 911 11