818 is a palindrome. Write it backwards and you have 818.

818 is an ambigram or strobogrammatic number. Rotate it 180 degrees and you still have 818.

The year 818 CE was a common year (not a leap year).

The year 818 CE started on a Friday.

In the United States, the 818 area code primarily covers the San Fernando Valley of Los Angeles, California.^{1}

818 was a short film made in 2012.^{2}

818 is used in the Dewey Decimal System for “Authors, American and American Miscellany”, or American miscellaneous writings in English.^{3}

In the United States, a hot dog is eaten about 818 times per second between Memorial Day and Labor Day.^{4}

818 written in Roman numerals is DCCCXVIII.

818 written in Chinese is 捌佰壹拾捌.^{5}

818 written in Egyptian hieroglyphics is .^{6}

818 is a polite number, since it can be written as a sum of consecutive natural numbers (\(203+204+205+206\)).

818 is a semiprime because it is a natural number that is the product of two prime numbers (\(2×409\)).

818 is a plaindrome in base 5 (\(11233_5\)), base 7 (\(2246_7\)), and base 13 (\(4\textrm{AC}_{13}\)). A plaindrome is a number in a given base \(b\) if its digits are in non-decreasing order in that base.

818 is a nialpdrome in base 16 (\(332_{16}\)). A number is a nialpdrome in a given base \(b\) if its digits are in non-increasing order in that base.

818 (\(1100110010_2\)) is digitally balanced in base 2, because in such base it contains all the possible digits an equal number of times.

\(818 = 2^2 + 3^2 + 4^2 + 5^2 + 6^2 + 7^2 + 8^2 + 9^2 + 10^2 + 11^2 + 12^2 + 13^2\)

## Footnotes

- “818 Area Code“.
*All Area Codes.com*. Accessed July 10, 2019. - “818 (2018)“.
*IMDB.com*. Accessed July 10, 2019. - “Melvil Decimal System: 818“.
*LibraryThing.com*. Accessed July 10, 2019. - Spector, Nicole. “818 Hot Dogs Eaten Every Second, and Other Memorial Day Facts“.
*NBC News.com*. May 26, 2017. Accessed July 10, 2019. - “818 in Chinese numeral is 捌佰壹拾捌“.
*Math.Tools*. Accessed July 10, 2019. - “818 in Egyptian numeral is “.
*Math.Tools*. Accessed July 10, 2019.