Palindromic number
Decimal palindromic numbers: Change of examples (multiples of 1221)
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All palindromic numbers with an even number of digits are divisible by [[11 (number)|11]].{{cite web |title=The Prime Glossary: palindromic prime |url=https://t5k.org/glossary/page.php?sort=PalindromicPrime |website=[[PrimePages]] |access-date=11 July 2023}} |
All palindromic numbers with an even number of digits are divisible by [[11 (number)|11]].{{cite web |title=The Prime Glossary: palindromic prime |url=https://t5k.org/glossary/page.php?sort=PalindromicPrime |website=[[PrimePages]] |access-date=11 July 2023}} |
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Similarly, if equal-interval multiples of 3 are half of 6-digit palindromes (e.g. |
Similarly, if equal-interval multiples of 3 are half of 6-digit palindromes (e.g. 345,543 and 852,258), all such palindromes (6-digit, 12-digit, 18-digit and so on) are multiples of 1,221 (11 × 111). |
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There are 90 palindromic numbers with three digits (Using the [[rule of product]]: 9 choices for the first digit - which determines the third digit as well - multiplied by 10 choices for the second digit): |
There are 90 palindromic numbers with three digits (Using the [[rule of product]]: 9 choices for the first digit - which determines the third digit as well - multiplied by 10 choices for the second digit): |
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