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Find the number:

it's less than $100$;

it's one more than a multiple of $3$;

exactly one of the digits is prime;

if you reverse its digits, you get a prime;

it has exactly four factors;

the sum of its digits is prime;

if you multiply it by $5$, the answer is greater than $100$.

If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.

*This problem is taken from the UKMT Mathematical Challenges.**View the archive of all weekly problems grouped by curriculum topic*

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