Determine the smallest base ten positive palindrome with exactly 4 distinct prime factors.

Going through the numbers with four distinct prime factors, from smallest up, I quickly arrived at 858.

2 *  3 *  5 *  7 = 210
2 *  3 *  5 * 11 = 330
2 *  3 *  5 * 13 = 390
2 *  3 *  5 * 17 = 510
2 *  3 *  7 * 19 = 570
2 *  3 *  5 * 23 = 690

2 *  3 *  7 * 11 = 462
2 *  3 *  7 * 13 = 546
2 *  3 *  7 * 17 = 714
2 *  3 *  7 * 19 = 798

2 *  5 *  7 * 11 = 770

2 *  3 * 11 * 13 = 858 <====
 

Posted by Dej Mar on 2012-09-23 13:12:57