830

[Math.]  8303 = 571,787,000 = (–57+17+870+00)3.


831

[Math.]  6×7×9×524×831 = 164,597,832, using each of 9 digits 1-9 once on both sides of the equality.

 

832...

 

833

[Phone]  An area code for the toll-free (or WATS: Wide Area Telecommunications Service) telephone number, dialing within the U.S. and Canada.

 

834

[World]  The ISO-3166 country code for Tanzania.

 

835...

 

836

[Math.]  621,770+77,126 = 8362 = 698,896 (a palindromic square number)

and 621,770–077,126 = 7382 = 544,644.

 

837...

 

838...

 

839

[Math.]  A prime number.

 

830-839

[Library]  Numbers 800-899 are the first 3 digits in Dewey Decimal Classification System call numbers for library books in Literature. Numbers 830-839 are for books in German Literature.