1,800 (separate page)

 

1,801

[Calendar]  The first year of the 19th century.

 

[Math.]  A prime number.

 

1,803

[History]  The year of the U.S. Louisiana Purchase appears on the back of the new U.S. nickel, minted in 2004.

 

1,806

[Math.]  The denominator of the 42nd Bernoulli number.

 

1,811

[Math.]  A prime number

 

1,816

[History]  The year 1816 is known throughout Europe and the Unites States as “the year without summer”, due to the eruption of Mount Tambora, a volcano in Indonesia, whose excess dust changed the weather all around the world: frosts and snow in northeastern US and colder tempters in parts of Europe.

 

1,822

[Phone]  The first 4 digits to be dialed for any 822/toll-free telephone number dialing within the U.S. and Canada.

 

1,823

[Math.]  A prime number.  A factor of Ramanujan constant: 196,884 = 22×33×1823 = 196,883+1.

 

[Math.]  18232 = 3,323,329.

 

1,830

[Math.]  A triangular number (sum of all integers from 1 to 60): 1830 = 1+2+…+59+60.

 

1,831

[Math.]  A prime number.

 

1,833

[Phone]  The first 4 digits to be dialed for any 833/toll-free telephone number dialing within the U.S. and Canada.

 

1,837

[Math.]  Two multiples of number 1837, 1837×2 = 3674 and 1837×7 = 12,859, use each of 9 digits 1-9 once.

 

1,844

[Phone]  The first 4 digits to be dialed for any 844/toll-free telephone number dialing within the U.S. and Canada.

 

1,847

[Math.]  A prime number.

 

1,848

[Math.]  18483 = 6,311,112,192 = (631+1–1+1219–2)3.

 

1,849

[History]  The year of the discovery of gold in Sierra Nevada, California. Then California state motto “Eureka!” was adopted.

 

1,852

[Measure]  The exact length (m, meters) of an international nautical mile.

1 knot = 1 nautical mile per hour = (1852/3600) m/s.

1 marine league = 3 nautical miles = 5556 m = 18228.347 ft (feet).

 

1,854

[Math.]  Subfactorial of 7: !7 = 1854.

 

1,855

[Phone]  The first 4 digits to be dialed for any 855/toll-free telephone number dialing within the U.S. and Canada.

 

1,861

[Math.]  A prime number.

 

1,863

[Math.]  Professor Umbugio’s famous “The End of the World” formula: the number 1492n–1770n–1863n+2141n is divisible by 1946, for all values of n up to 1945, where 1492, 1770, 1863 are the year of the Discovery of the New World by Christopher Columbus, the Boston Massacre and the Gettysburg Address, respectively. (E. Starke, Professor Umbugio’s prediction, American Mathematical Monthly, 54, January 1947.)

 

1,866

[Phone]  The first 4 digits to be dialed for any 866/toll-free telephone number dialing within the U.S. and Canada.

 

1,867

[Math.]  A prime number.

 

1,871

[Math.]  A prime number.

 

1,873

[Math.]  A prime number.

 

1,877

[Math.]  A prime number.

 

[Phone]  The first 4 digits to be dialed for any 877/toll-free telephone number dialing within the U.S. and Canada.

 

1,881

[Math.]   

33×34 = 1122

33×35 = 1155

33×36 = 1188

33×37 = 1221

33×47 = 1551

33×57 = 1881

 

333×334 = 111,222

333×335 = 111,555

333×336 = 111,888

333×337 = 112,221

333×347 = 115,551

333×357 = 118,881

 … (generalizable pattern) … 

 

1,882

[Movie]  Name of TV show/series or movie: “Cartel 1882”.

 

1,888

[Phone]  The first 4 digits to be dialed for any 888/toll-free telephone number dialing within the U.S. and Canada.

 

1,889

[Math.]  A prime number.

 

1,890

[Library]  ISBN-1-890 is the International Standard Book Number for books published by Smart Publication.

 

1,891

[Math.]  A triangular number (sum of all integers from 1 to 61): 1891 = 1+2+…+60+61.

 

1,896

[Sport]  The first year of the modern Olympic Games (Athens, Greece).

 

1,899

[Tech.]  The year Charles H. Duell, Commissioner of the U.S. Office of Patents predicted terribly mistakenly: “Everything that can be invented has been invented!