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What number has 48 divisors?(Click here to view the original thread with full colors/images)
Posted by: [IS]XXX
This should be fun 
Posted by: Kaje
420. 
Posted by: [IS]XXX
Close, you only have half (24)
C'mon, you math g33ks have to do better than that! Although, of course, to the best of MY knowledge, there's no mathematical way to find the answer, except guessing at random, however, that's beside the point, and I only have the knowledge of a HS Frosh.
Posted by: Kaje
420 has 48 divisors.
1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 42, 60, 70, 84, 105, 140, 210, 420
-1, -2, -3, -4, -5, -6, -7, -10, -12, -14, -15, -20, -21, -28, -30, -35, -42, -60, -70, -84, -105, -140, -210, -420
Posted by: [IS]XXX
...
Okay, how about positive integers only? Yeah... What number has 48 positive integer divisors?
bastard  |
Posted by: Kaje
Posted by: [IS]XXX
Alright, that's it. Who has the store of sharp and pointy sticks?
/me stares at ogee
Posted by: RDevz
quote:
Originally posted by [IS]XXX
Close, you only have half (24)
C'mon, you math g33ks have to do better than that! Although, of course, to the best of MY knowledge, there's no mathematical way to find the answer, except guessing at random, however, that's beside the point, and I only have the knowledge of a HS Frosh.
I'm sure that there's something to be done with prime factors, but to be honest, I can't be arsed. 
Posted by: bazie
If you multiply 1*2*3*5*7*11*13*17...*47th prime number you would get a number with 48 divisors.....but it would be really large
btw, what is 1 again? I seem to remember it being neither prime nor composite but having some fancy name...although it was years ago that i learnt it, maybe elementary school or something.
Posted by: [IS]XXX
Need a hint? It's 12 digits or less
Posted by: bazie
quote:
Originally posted by [IS]XXX
Need a hint? It's 12 digits or less
look here, everyone and his dog is capable of find a number with 48 deviders...just multiply any 48 numers (that are either prime or composed of prime numbers you have already inclused)together and that number will have 48 devisors. now stfu
Posted by: RDevz
quote:
Originally posted by bazie
look here, everyone and his dog is capable of find a number with 48 deviders...just multiply any 48 numers (that are either prime or composed of prime numbers you have already inclused)together and that number will have 48 devisors. now stfu
But not precisely 48 divisors.
Posted by: RDevz
Duh. 2^47
Divisors are 2^0 through 2^47. Precisely 48 divisors. 
Posted by: bazie
quote:
Originally posted by RDevz
But not precisely 48 divisors.
i don't care about precision
Posted by: bazie
quote:
Originally posted by RDevz
Duh. 2^47
Divisors are 2^0 through 2^47. Precisely 48 divisors.
now find the LOWEST number with 48 divisors
Posted by: RDevz
quote:
Originally posted by bazie
now find the LOWEST number with 48 divisors
No.
I'll see how bored I am later.
Posted by: bazie
umm...ok, fucker, 4200 has 48 divisors, exactly, all positive, and is the smallest possible one
For example, 4200 is 2^3*3^1*5^2*7
so that is 2*2*2*3*5*5*7
factors of 1, 2,,3,4,5,6,7, 8,10,14,15,12,20,21, 25, 28,30,35, 42,50,70,75, 24,40,56,60,84,100,105, 140,120, 168, 200, 280, 525, 4200, 2100, 1400, 1050, 840, 700, 600, 420, 300, 350,210,500, 175
Too lazy to go back and order that now
Ok, it works becasue the 2^3 = 8 which has 4 factors. 3^1 has two factors. 5^2 has 3 factors and 7^1 has two factors. Each factor can be multiplied by each other factor so....4*2*3*2 = 48
So one way of finding numbers that have exactly (me glares at rdevz) 48 devisors is to take prime numbers and have 1 to the power of 3, one to the power of 2 and two to the power of 1.
Posted by: bazie
also, that has to be the lowest, because 2,3,5,7 are the 4 lowest primes
Posted by: PlasmaSamurai
If you're stuck you can always go to www.mathnerds.com or www.math.com
Posted by: bazie
quote:
Originally posted by PlasmaSamurai
If you're stuck you can always go to www.mathnerds.com or www.math.com
I will not click those links. It takes a genious to figure what i just did out! A genious!!
Posted by: Kaje
Bitch, I won 19 posts ago.
It's spelled "genius".
Posted by: bazie
quote:
Originally posted by PlasmaSamurai
If you're stuck you can always go to www.mathnerds.com or www.math.com
I clicked the links. I have a new email. bazie@math.com
Posted by: PlasmaSamurai
Beware what you're getting yourself into bayzie
Posted by: bazie
quote:
Originally posted by PlasmaSamurai
Beware what you're getting yourself into bayzie
o?
this is sweet...now i can PROVE to people that i am a nerd!
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