Unique semiprime number (Posted on 2010-04-17)

	Submitted by Ady TZIDON
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Ans: 689 There are six non-prime digits -0, 1,4,6,8,&9.: :  Zero cannot be a part of a 3 digit number whose digits are in strictly ascending order: So there are ten combinations of three-digit numbers with digits in ascending order using the 5 digits -1,4,6,8, and 9: 146, 148, 149, 168, 169, 189, 468, 469, 489, 689: Of these, four are even.  : This leaves: 149, 169, 189, 469, 489, 689: 149 is prime, therefore has no prime divisors.: 169 = 13*13 so the two divisors are not distinct: 189 = 3³ * 7, cannot form two prime divisors.: 489 = 3 * 163, no two- digit divisors. : This leaves 689 = 13 * 53  :

	Subject	Author	Date
	Puzzle Answer	K Sengupta	2023-09-18 02:25:28
	re: Solution- a tiny remark	Ady TZIDON	2010-04-17 17:05:37
	Solution	hoodat	2010-04-17 14:37:10