210 (separate page)

 

211

[Math.]  Reversible numbers and their squares: 1122 = 12544 and 2112 = 44521.

Three square numbers using the same digits: 1122 = 12544, 2112 = 44521 and 2292 = 52441.

 

[Math.]  A prime number, formed by 3 consecutive Fibonacci numbers in reverse order: 2, 1 and 1.

 

[Math.]  2113 = 9,393,931.

 

[Math.]  (121+878 = 999 = 101+898)

1212 = 014,641 & 014+641 = 655

8782 = 770,884 & 770+884 = 1654 and 1+654 = 655.

and

1012 = 010,201 & 010+201 = 211

8982 = 806,404 & 806+404 = 1210 and 1+210 = 211.

 

[Phone]   An NANPA/U.S. telephone area code reserves for coin phone refunds. This number cannot be used as area code. (NANPA: North American Numbering Plan Administration).

 

[Phone]  A 7-digit number after an NANPA/U.S. 3-digit area code cannot start with 0nm, 1nm or 8 other 3-digit numbers: 211, 311, 411, 511, 611, 711, 811 and 911.

 

 212

[Math.]  2122 = 44,944.

 

[Math.] (232+767 = 999 = 212+787)

2322 = 053,824 & 053+824 = 877

7672 = 588,289 & 588+289 = 877

and

2122 = 044,944 & 044+944 = 988

7872 = 619,369 & 619+369 = 988.

 

[Phone]  International telephone dialing code for Morocco.

 

[Science]  The boiling point of water: 100 oC (Celsius or centigrade) = 212 oF (Fahrenheit) = 373.15 K (Kelvin).

 

[World]  The ISO country code for Dominica. (ISO-3166)

 

213

[Math.]  25,986 = 213×122 and backward 312×221 = 68,952.

 

[Phone]  International telephone dialing code for Algeria.

 

214 

[Language]  The Kangxi Zidian dictionary, published in 1716 contains 47035 Chinese characters, plus 1995 graphic variants, totally 49,030 different characters, which are grouped under 214 radicals. (To be verified).

 

[World]  The ISO country code for Dominican Republic. (ISO-3166)

 

215

[Math.]  2153 = 9,938,375 = (99+38+3+75)3.

 

[Tech.]  Automobile tires used in the U.S. have tire section width of 145, 155, 165, 175, 185, 195, 205, 215, 225, 235, 245 or 255 (millimeters).

 

[Trivia]  The Paper House at Pigeon Cove (Rockport, Massachusetts) was built entirely of newspaper and even most of furniture. Its walls are made of with 215 layers of newspaper and are one inch thick.

 

216

[Math.]  The only cube number that is the sum of 3 consecutive cube numbers: 216 = 63 = 33+43+53.

 

[Math.]   A base system of multigrade equalities: (References [26])

1+15+22+50+57+71 = 2+11+27+45+61+70 = 5+6+35+37+66+67 = 216

12+152+222+502+572+71222+112+272+452+612+702  

                                           = 52+62+352+372+662+672 = 11,500

13+153+223+503+573+71323+113+273+453+613+703 =  

                                           = 53+63+353+373+663+673 = 682,128

14+154+224+504+574+71424+114+274+454+614+704

                                           = 54+64+354+374+664+674 = 42,502,564

15+155+225+505+575+715 = 25+115+275+455+615+705 =

                                           = 55+65+355+375+665+675 = 2,724,334,416.

Multigrade equalities still hold by adding any integer n to every base term in both sides.  Hence, the base equality always has number 1 appearing in one side.

 

[Phone]  International telephone dialing code for Tunisia.

 

[Sport]  The number of stitches on the surface of a baseball.

 

[Trivia]  The shorter side (mm, millimeters) of the U.S. standard paper size “Letter” (279 mm×216 mm, 11 in×8.5 in), comparable to the international standard paper size A4 (297 mm×210 mm).

 

[Trivia]  The shorter side (mm, millimeters) of the U.S. standard paper size “Legal” (356 mm×216 mm or 14 in×8.5 in).

 

217

 

218

[Phone]  International telephone dialing code for Libya.

 

[World]  The ISO country code for Ecuador. (ISO-3166).

 

219

[Math.]  Sum 219+438 = 657 is one of only 4 cases that the equality: n+2n = 3n use each of 9 digits 1-9 once: n = 192, 219, 273 and 327.

  

210-219

[Library]  Numbers 200-299 are the first 3 digits in Dewey Decimal Classification System call numbers for library books in Religion and Theology. Numbers 210-219 are for books in Natural Theology.

 

200-299 

[Education]   The numbers commonly assigned for graduate courses in most U.S. universities and colleges.

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References [26]