A four digit palindrome number multiplied by 45 becomes a five digit palindrome number. What is the five digit palindrome number?

A four digit palindrome number multiplied by 45 becomes a five digit palindrome number. What is the five digit palindrome number?

Let four digits be 1000x + 100y + 10Y + X, five digits = 45 * (1000x + 100y + 10Y + x) = 45045x + 4950y. Analysis: X can only take 1 or 2, otherwise it will become 6 digits. 45045x determines that one digit is 0 or 54950y is 0, so x can only take 1, that is, five digits = 45045 + 4950y