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I remember it well

I am a bit vague about my bank security number-

It is a four figure number (or possibly five);

It uses four different digits (or possibly five);

The first digit is four (or possibly five);

The second digit is four (or possibly five) and none of the other digits is smaller;

The number is a prime multiplied by four (or possibly five);

If you reverse the order of the digits you get a number which is the product of four (or possibly five) different primes;

In four (or possibly five) of these statements my first guess is correct.

What is my bank security number?

WIN £15 will be awarded to the sender of the first correct answer opened on Wednesday 22 September. The Editor’s decision is final. Please send entries to Enigma 1609, New ÐÓ°ÉÔ­´´, Lacon House, 84 Theobald’s Road, London WC1X 8NS, or to enigma@newscientist.com (please include your postal address).

Answer to 1603 A double sum: FOURTEEN = 35617889

The winner Graham Clarke of Edinburgh, UK