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Abstract

Prime numbers have fascinated man for years; they are the source of many questions and have led to the identification of many important concepts. This article gives some interesting ideas about primes, such as: there are an infinite number of palindromic primes such as 313, 929, 73,637; there are, however, also “reversibles” which are not palindromic. For example, there are 93 five-digit palindromes such as 35153 but there are 1,366 other reversibles that are prime but are not palindromic. Palindromes and reversibles must begin and end with 1, 3, 7, or 9. Palindromes cannot have an even number of digits, but this is not true of reversibles. A unique six-digit prime is 193939, which is reversible and cyclic. The six numbers formed by successively moving the initial digit to the end are each reversible. Similarly, 11939 is unique among five-digit primes. There are no such numbers with four or seven digits.