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GeneralThe six rightmost non-zero digits of 1000000! Pin
Rod Gowdy2-Jul-08 4:50
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GeneralRe: The six rightmost non-zero digits of 1000000! [modified] Pin
Robert.C.Cartaino2-Jul-08 6:33
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GeneralRe: The six rightmost non-zero digits of 1000000! Pin
Rod Gowdy3-Jul-08 3:42
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GeneralRe: The six rightmost non-zero digits of 1000000! Pin
Robert.C.Cartaino3-Jul-08 10:06
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QuestionSpecify numbers as product of Primes? Pin
Ian Uy25-Jun-08 19:37
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AnswerRe: Specify numbers as product of Primes? Pin
cp987625-Jun-08 21:32
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GeneralRe: Specify numbers as product of Primes? Pin
Ian Uy26-Jun-08 0:42
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AnswerRe: Specify numbers as product of Primes? Pin
Robert.C.Cartaino26-Jun-08 4:48
memberRobert.C.Cartaino26-Jun-08 4:48 
Ian Uy wrote:
I'm lost on how to begin to tackle this problem. Please advice.


As a college student, you really should be able to do this. It's basic math.

What you will want to search for is called "prime factorization." The easiest-to-understand technique is called "trial division."

On paper, you start by writing down your large number (let's call it 'n'). Then try to think of another number which divides evenly into n without any remainder. That number is a factor of n. It's easiest to start with small numbers.

In your example, what number divides evenly into 120? How about 2? Yes, 120/2=60. So write down 2 and 60 (those are factors of 120, but not necessarily prime).

Then try to factor each number you wrote down (the 2 and the 60). Are there any numbers (other than 1) that divide into 2 evenly? No, so 2 is a "prime factor" of 120 (i.e. 2 cannot be divided any further).

How about the 60? 60/2=30. So, there is another 2 that is a prime factor of 120. So far we have the factors of 120=2,2,30. Now factor the 30 and keep going.

Keep going until you run out of numbers that can be divided evenly. Those will be your prime factors.

120 factored = 2,60 (2 is prime)
60 factored = 2,30 (2 is prime)
30 factored = 2,15 (2 is prime)
15 factored = 3,5 (both 3 and 5 are prime)
Done.

The prime factors of 120 are (from the parentheses above) 2,2,2,3,5.

Now try writing that in code and see what you come up with. You can use this Table of Prime Factors[^] to check your answers.
GeneralRe: Specify numbers as product of Primes? Pin
Ian Uy26-Jun-08 4:50
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GeneralRe: Specify numbers as product of Primes? Pin
The Developer8-Aug-08 7:03
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GeneralRe: Specify numbers as product of Primes? Pin
Ian Uy26-Jun-08 6:28
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GeneralRe: Specify numbers as product of Primes? Pin
Paul Conrad28-Jun-08 5:44
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GeneralRe: Specify numbers as product of Primes? Pin
Ian Uy28-Jun-08 5:46
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GeneralRe: Specify numbers as product of Primes? Pin
Paul Conrad28-Jun-08 6:11
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GeneralRe: Specify numbers as product of Primes? Pin
Ravi Bhavnani8-Aug-08 7:16
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GeneralRe: Specify numbers as product of Primes? Pin
cp987628-Jun-08 20:27
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GeneralRe: Specify numbers as product of Primes? Pin
Luc Pattyn29-Jun-08 2:42
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GeneralRe: Specify numbers as product of Primes? Pin
MarkBrock27-Jun-08 18:46
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GeneralRe: Specify numbers as product of Primes? Pin
Paul Conrad28-Jun-08 5:42
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GeneralRe: Specify numbers as product of Primes? Pin
ChandraRam2-Jul-08 22:49
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GeneralRe: Specify numbers as product of Primes? Pin
MarkBrock2-Jul-08 23:06
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AnswerRe: Specify numbers as product of Primes? Pin
Member 419459326-Jun-08 8:19
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GeneralRe: Specify numbers as product of Primes? Pin
Robert.C.Cartaino26-Jun-08 8:47
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GeneralRe: Specify numbers as product of Primes? Pin
Ian Uy26-Jun-08 17:51
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GeneralRe: Specify numbers as product of Primes? Pin
cp987629-Jun-08 14:57
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