mersenneforum.org hello I am new here
 Register FAQ Search Today's Posts Mark Forums Read

 2008-03-10, 20:38 #1 n1994   Mar 2008 17 Posts hello I am new here I wanted to ask if 73786976290543239167 is prime. Last fiddled with by Kosmaj on 2008-03-11 at 02:45
 2008-03-10, 21:48 #2 akruppa     "Nancy" Aug 2002 Alexandria 2,467 Posts Nope, 73786976290543239167 = 3391 * 12113 * 14369 * 125018321 Alex
 2008-03-11, 02:47 #3 Kosmaj     Nov 2003 2×1,811 Posts n1994 Welcome to Mersenne Forum! You can ask us about primality of much larger numbers.
 2008-03-11, 06:14 #4 VBCurtis     "Curtis" Feb 2005 Riverside, CA 2·32·257 Posts To factor small numbers (anything below 10^40 or so), google "ecm factoring". The first link is to a java applet that factors small numbers very quickly. Numbers larger than 10^40 can also be done, but may take a while (the larger the number, the longer the factoring process may take). Numbers of the size you originally asked about take seconds. -Curtis
 2008-03-11, 13:23 #5 n1994   Mar 2008 1116 Posts thanks I want to ask you about 18889465931478580871167 and how do you check if its prime?
 2008-03-11, 13:26 #6 n1994   Mar 2008 218 Posts and 885470737341981130751
 2008-03-11, 13:34 #7 n1994   Mar 2008 1710 Posts last numbers: 23611832414348226068479
2008-03-11, 13:39   #8
Mini-Geek
Account Deleted

"Tim Sorbera"
Aug 2006
San Antonio, TX USA

102538 Posts

Quote:
 Originally Posted by n1994 last numbers: 23611832414348226068479
Please find it for yourself, using VBCurtis's instructions (below).
Quote:
 Originally Posted by VBCurtis To factor small numbers (anything below 10^40 or so), google "ecm factoring". The first link is to a java applet that factors small numbers very quickly. Numbers larger than 10^40 can also be done, but may take a while (the larger the number, the longer the factoring process may take). Numbers of the size you originally asked about take seconds. -Curtis
c.f. vg'f cevzr

2008-03-11, 13:41   #9
retina
Undefined

"The unspeakable one"
Jun 2006
My evil lair

23×751 Posts

Quote:
 Originally Posted by n1994 last numbers: 23611832414348226068479
You can even go here also:

2008-03-11, 13:43   #10
retina
Undefined

"The unspeakable one"
Jun 2006
My evil lair

23·751 Posts

Quote:
 Originally Posted by Mini-Geek Please find it for yourself, using VBCurtis's instructions (below). c.f. vg'f cevzr
Unun, lrnu vg vf cevzr, fb rnfl gb purpx.

 2008-03-11, 15:43 #11 akruppa     "Nancy" Aug 2002 Alexandria 2,467 Posts Here's another good page to factor numbers: http://www.alpertron.com.ar/ECM.HTM Alex