294284941888956266345982392040522594123776
Now comes the cheating:
Dim i As String
Dim L As Integer
Dim j As Integer
Dim m As Integer
Dim sM As String
Dim Doubled As String
Dim CarryFlag As Integer
i = "73571235472239066586495598010130648530944"
L = LEN(i)
Print L
FOR j = L TO 1 STEP -1
m = Cast(Integer, Mid(i, j, 1))
Print "M = "; m
m = m * 2
Print "M = "; m; " CarryFlag = "; CarryFlag
IF CarryFlag = 1 THEN
Print "CarryFlag = 1"
m = m + 1
CarryFlag = 0
END IF
IF m >= 10 Then
Print "M = "; m; " CarryFlag = "; CarryFlag
m = m - 10
CarryFlag = 1
END IF
'PRINT "Counting down: "; MID$(i$, j, 1)
Doubled = str(m) + Doubled
'PRINT j, M
NEXT j
IF CarryFlag = 1 THEN Doubled = "1" + Doubled
PRINT Doubled
Should be good for any number up to 32767 bytes in length.
Compiled with FreeBASIC using the FbEdit IDE.