Six of the factors of 1221 are palindromes: {1,3,11,33,111,1221} but two are not: {37,407}
(A) What number under one million has the most palindrome factors?
Some numbers have only palindromes as factors. Examples include 88: {1,2,4,8,11,22,44,88} and any palindromic prime
(B) Find the smallest number with at least as many palindrome factors as part (A) but having only palindrome factors.
(In reply to
My thoughts on the difficulty of part (B) by Jer)
"multiplying this by palindrome prime of the form 10...010...01"
A number of that form will always be a multiple of 3 and therefore not prime and therefore leading to possible carries in the multiplication by the 3 or certainly by the 100...010...001 number divided by 3 when forming some other divisors.
Edited on March 15, 2022, 9:23 pm
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Posted by Charlie
on 2022-03-15 21:20:42 |
re: My thoughts on the difficulty of part (B)
