There are two Mathematica boolean test functions about numbers
or numeric objects: `NumberQ`

and `NumericQ`

.
In Mathematica there are expressions that are numeric but not not
numbers.

```
In[2]:= Prepend[{InputForm[#],NumberQ[#],NumericQ[#]}&/@{1,1.1,Pi,E,3/4,Sqrt[2]},{x,"NumberQ[x]","NumericQ[x]"}]//TableForm
Out[2]//TableForm=
x NumberQ[x] NumericQ[x]
1 True True
3/4 True True
1.1 True True
Sqrt[2] False True
Pi False True
E False True
```

If the object involves `Unevaluated`

and
`Hold`

, it can be a little more subtle

```
NumericQ[Unevaluated[1 + 1]]
Out[33]= False
```