riddle
12-11-2018, 09:34 PM (This post was last modified: 12-11-2018 09:43 PM by Don Shepherd.)
Post: #7
 Don Shepherd Senior Member Posts: 724 Joined: Dec 2013
RE: riddle
(12-11-2018 06:00 PM)Albert Chan Wrote:  223092870 = 2·3·5·7·11·13·17·19·23

This SS# had huge number of factors = 2^9 = 512

For valid SS# (i.e. 9 digits limits), what number have most factors ?

Edit: these 9-digits numbers have maximum of 1344 factors
http://math.univ-lyon1.fr/~nicolas/ramanujanNR.pdf, page 152

735134400 = 2^6 * 3^3 * 5^2 * 7 * 11 * 13 * 17
821620800 = 2^6 * 3^3 * 5^2 * 7 * 11 * 13 * 19
931170240 = 2^6 * 3^2 * 5 * 7 * 11 * 13 * 17 * 19
994593600 = 2^6 * 3^3 * 5^2 * 7 * 11 * 13 * 23
Albert, thanks for that reference. Very interesting.

I have a program on my 12c+ that can verify the number of factors pretty quickly.
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 Messages In This Thread riddle - Don Shepherd - 12-11-2018, 01:41 PM RE: riddle - Joe Horn - 12-11-2018, 04:32 PM RE: riddle - Don Shepherd - 12-11-2018, 05:08 PM RE: riddle - Albert Chan - 12-11-2018, 05:28 PM RE: riddle - Don Shepherd - 12-11-2018, 05:38 PM RE: riddle - Joe Horn - 12-12-2018, 06:43 AM RE: riddle - Albert Chan - 12-11-2018, 06:00 PM RE: riddle - Don Shepherd - 12-11-2018 09:34 PM

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