Question by smci: Numbers with interesting alphanumeric names?
Some numbers have interesting alphanumeric names (800-FLOWERS).
Usually these are seven digits, or for longer phrases, some choice of SeVEN leTTeRs.
I’m looking for curious, funny, geeky or naughty names which have some connection to their numeric value.
Useful converter: http://www.csgnetwork.com/phonenumcvtrev.html
(For reverse conversion, there are ~3^7 names for a given number, the vast majority of which are linguistically impossible, if anyone finds a useful reverse-translator which prunes out impossible letter sequences, let us know?)
“MERSENNe” → 63773663 which is indeed prime (moreover, a truncatable prime, but not a Mersenne prime (aww)). This was already discovered.
“FERMAT” → 337628 = 2^2 * 84407, can you do anything with that?
“COMPOSITE” → 266767483 = 131 * 2036393
“FACTORS” → 3228677 = 241 * 13397
“PRIMALITY” → 774625489 which is vaguely ironically = 11 * 31 * 293 * 7753
I just discovered “SEMIPRIME” which is semiprime → 736477463 = 15733 * 46811 , and “(se)MIPRIME” → 6477463 (prime).
Also, “ERATOSTHENES” is not prime but “eRATOSTHENES” is → 72867843637
Neat huh?
Can you do better? (bonus points if it’s mathematical)
It’s trivially easy to write a conversion function, then pipe a wordlist into it. Reverse-searching for a meaningful name to a number is harder. This is definitely a question that lends itself to automation, maybe falzoon will tackle it.
The same idea already occurred to various people:
(Donald S. McDonald on alt.math in 2006), he also tries playing with other number bases like base-27:
http://www.mathkb.com/Uwe/Forum.aspx/maths/2388/PROOF-2-3-5-7-DIVIDES-2-PRIME-2-FOR-P-30-402-457
or this guy, who points out the probability of a random 7-digit number being prime is 7%, or 4.4% for 10-digit:
http://divisbyzero.com/2009/09/03/more-prime-phone-numbers/
FERMAT → 337628 = F₁*F₄ +38F₃ +11F₂ -2 F₁
= 5*65537 +38*257 + 11*17 -2*5
Best answer:
Answer by falzoon
EVEN → 3836
ODD → 633
I’ll try and think of some more over the next few minutes before I go to sleep.
FACTORED → 32286733 (= 23 x 331 x 4241)
NUMBER → 686237 (that was easy)
INTEGER → 4683437 (just filling up space now)
TWO → 896 (= 7 x 2 x 2 x 2 x 2 x 2 x 2 x 2, which is 7 lots of 2^7) (hey! I’m sleepy)
FACTORTHREE → 32286784733 (= 7 * 61 * 75613079, i.e. 3 factors)
e → 3 (which is 2.718281828… to the nearest integer)
TRIANGLE → 87426453 (= 3 x 29142151, i.e. an equilat.triangle with sides 29142151)
PENTAGONAL → 7368246625 (= 5 x 5 x 5 x 31 x 103 x 18461) (a majority of 5′s)
CUBICS → 282427 (= 3^3 + 27^3 + 29^3 + 62^3)
SQUARES → 7782737 (= 36^2 + 44^2 + 81^2 + 2788^2)
PERFECT → 7373328 (of course, perfectly, sum of its digits = 6, and it ends in 28)
DEFICIENT → 333424368 (sum of factors, 1 + 2 + 3 + 29 + 79843, is < the number)
NUMBEROFTHEBEAST → 6862376384323278 (it's interspersed with irrelevant digits)
Getting off-track here - getting sleepy again.
FERMAT → 337628 (= 271^2 + 514^2 - 3^2 = 326^2 + 481^2 - 3^2)
which shows that 271^2 + 514^2 = 326^2 + 481^2.
Not a good relationship with the name, but hopefully, of some close-felt interest.
COMBINATION → 26624628466 (a combination of all the positive, even digits)
CHAINING →24246464
PELL → 7355 (Fundamental solution : 3048865209^2 - 7355 * 35550596^2 = 1)
UNLUCKY → 8658259 (= 13^6 + 10*13^5 + 4*13^4 + 13^3 + 12*13^2 + 4*13^1 - 13^0)
(No doubt about it, that's a very unlucky number)
KEPLER → 537537 (final digit sum of each 537 is 6, and 6 + 6 = 12, which strongly
indicates why it was Kepler who first described the rhombic dodecahedron, which has
12 faces).
FIBONACCI → 342662224 (= 267914296 + 63245986 + 9227465 + 2178309 + 75025
+ 17711 + 2584 + 610 + 233 + 5, which are all Fibonacci numbers in the order -
F42 + F39 + F35 + F32 + F25 + F22 + F18 + F15 + F13 + F5
EQUATION → 37828466 (3 + 7 = 8 + 2 and 8 + 4 = 6 + 6)
Dimensional Spookiness - where the following three can be arranged like this :
LENGTH → 536484 (= 1^1 * 536484)
AREA → 2732 (= 2^2 * 683)
VOLUME → 865863 (= 3^3 * 32069)
POWER → 76937 (= 3^2 + 152^2 + 232^2)
POWERS → 769377 (= 5^2 + 74^2 + 874^2)
POWERED → 7693733 (= 902^2 + 2623^2)
POWERING → 76937464 (= 6^2 + 1612^2 + 8622^2)
POWERFUL → 76937385 (= 5^2 + 5456^2 + 6868^2)
POWERHUNGRY → 76937486479 (= 98387^2 + 110915^2 + 117179^2 + 203038^2)
HUMUNGOUSLYPOWERFUL → 4868646875976937385
(= 1155256301^2 + 1879901528^2)
SUMOFTHREESQUARES → 78663847337782737
(= 7^2 + 135467692^2 + 245585732^2)
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