How to determine the number of common factors?
 

Does anyone have any suggestions on how to determine the number of common
factors based on given number? For example,
10 is given in cell A1, then the common factors for 10 are 1,2,5,10. There
are 4 numbers for common factors, then I will return 4 in cell B1.
I will try different number in cell A1,
Does anyone have any suggestions on how to determine the number of common
factors in cell B2?
Thanks in advance for any suggestions
Eric

How to determine the number of common factors?
 

Use the function below. Call with

=NumberFactors(10)

Function NumberFactors(target)

'include target
'then you only need to check 1/2 the numbers
NumberFactors = 1
For i = 1 To target / 2
If target Mod i = 0 Then
NumberFactors = NumberFactors + 1
End If
Next i

End Function


"Eric" wrote:

Does anyone have any suggestions on how to determine the number of common
factors based on given number? For example,
10 is given in cell A1, then the common factors for 10 are 1,2,5,10. There
are 4 numbers for common factors, then I will return 4 in cell B1.
I will try different number in cell A1,
Does anyone have any suggestions on how to determine the number of common
factors in cell B2?
Thanks in advance for any suggestions
Eric

How to determine the number of common factors?
 

Try this:

=SUMPRODUCT(--(MOD(A1,ROW(INDIRECT("1:"&A1)))=0))

Works only with integers. If the number is 0 you'll get an error. If it's
possible that the number can be 0 then use this version:

=IF(AND(ISNUMBER(A1),A1=0),1,SUMPRODUCT(--(MOD(A1,ROW(INDIRECT("1:"&A1)))=0)))

--
Biff
Microsoft Excel MVP


"Eric" wrote in message
...
Does anyone have any suggestions on how to determine the number of common
factors based on given number? For example,
10 is given in cell A1, then the common factors for 10 are 1,2,5,10. There
are 4 numbers for common factors, then I will return 4 in cell B1.
I will try different number in cell A1,
Does anyone have any suggestions on how to determine the number of common
factors in cell B2?
Thanks in advance for any suggestions
Eric

How to determine the number of common factors?
 

Improvement:

This takes care of 0 in a different way and accounts for an empty cell:

=IF(A1="","",SUMPRODUCT(--(MOD(A1,ROW(INDIRECT("1:"&MAX(1,A1))))=0)))

--
Biff
Microsoft Excel MVP


"T. Valko" wrote in message
...
Try this:

=SUMPRODUCT(--(MOD(A1,ROW(INDIRECT("1:"&A1)))=0))

Works only with integers. If the number is 0 you'll get an error. If it's
possible that the number can be 0 then use this version:

=IF(AND(ISNUMBER(A1),A1=0),1,SUMPRODUCT(--(MOD(A1,ROW(INDIRECT("1:"&A1)))=0)))

--
Biff
Microsoft Excel MVP


"Eric" wrote in message
...
Does anyone have any suggestions on how to determine the number of common
factors based on given number? For example,
10 is given in cell A1, then the common factors for 10 are 1,2,5,10.
There
are 4 numbers for common factors, then I will return 4 in cell B1.
I will try different number in cell A1,
Does anyone have any suggestions on how to determine the number of common
factors in cell B2?
Thanks in advance for any suggestions
Eric