Enigma 1132: Phone back
16 January 2017
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From New Scientist #2288, 28th April 2001 [link]
The PIN code on George’s cash card is a semi-prime number, that is to say it is the product of two different prime numbers. He discovered some time ago that the PIN code multiplied by his car registration number gives his six-digit phone number, which does not begin with a zero. But George has now discovered a slightly more obscure coincidence. If he subtracts his house number from his phone number and multiplies the result by his house number, the result is his phone number with its digits in reverse order!
What is George’s car registration number?