'handy prime number tester, param is long and function is boolean
Function testPrimes(param As Long) As Boolean

'two variables used
Dim x As Integer
Dim ceil As Double

'ceil rounds param to keep O(n) brief
ceil = Math.Round(Math.Sqr(param))

'basic prime number logic
If param = 1 Then
    testPrimes = True

ElseIf param = 2 Then
    testPrimes = True

ElseIf param Mod 2 = 0 Then
    testPrimes = False

Else
    For x = 3 To ceil
        If param Mod x = 0 Then
            testPrimes = False
            x = x + 2
        End If
    Next x

testPrimes = True

End If

End Function