Symmetrical numbers, also known as palindromic numbers, are numbers that remain the same when their digits are reversed. For example, the number 121 reads the same forwards and backwards, making it symmetrical. These numbers can be found in various numerical systems, including decimal and binary. Symmetrical numbers can be of any length, such as 7, 44, or 12321. They are often used in mathematics and number theory for various purposes, including puzzles and patterns. Their unique property makes them interesting to both mathematicians and enthusiasts alike.