198 (number)

1, 2, 3, 6, 9, 11, 18, 22, 33, 66, 99, 198 198 (one hundred [and] ninety-eight) is the natural number following 197 and preceding 199.Vanovschi Vitalii Properties of the number 197 http://www.numberempire.com:80/197 2026-09-27 www.numberempire.com en In mathematics 198 is the smallest number that can be written as a sum of four positive squares in ten different ways.Mathematical Association of America 2012-10-25 NumberADay 198 http://maanumberaday.blogspot.com/2012/10/198.html 2023-06-04A025366 - OEIS https://oeis.org/A025366 2023-06-04 oeis.org There are 198 positive palindromic numbers under 10,000.Khovanova Tanya Properties of 198 https://numbergossip.com/198/ Number Gossip 2026-09-27 198 is a Harshad number since the sum of the digits is 18, and which the sum is a whole number.Number 198 - Harshad Number, Properties & Facts NumberWorld https://numberworld.info/198 2026-09-27 numberworld.info en 198 is a Pell–Lucas number. Its corresponding Pell number is 70.A002203 - OEIS https://oeis.org/A002203 2023-06-04 oeis.org 198 is a practical number,A005153 Practical numbers: positive integers m such that every k < sigma(m) is a sum of distinct divisors of m. Also called panarithmic numbers. and a 5-tuple of practical numbers.Weisstein Eric W. Practical Number https://mathworld.wolfram.com/PracticalNumber.html 2026-09-27 mathworld.wolfram.com Wolfram Research, Inc. en 198 is the only number such that it equals the sum of its digits times 1.1. In other fields 198 is the number of ridges on a U.S. dollar coin.2022-08-18 Why Do Coins Have Ridges? Mental Floss https://www.mentalfloss.com/article/28044/how-many-ridges-are-quarter-and-why-are-they-there-first-place 2022-08-24 https://web.archive.org/web/20220818064144/https://www.mentalfloss.com/article/28044/how-many-ridges-are-quarter-and-why-are-they-there-first-place 2022-08-18 References 1 Category:Integers