NumberQ

NumberQ[expr] returns True if expr is numeric, otherwise False.

Attributes[NumberQ] := {Protected}

Simple examples

In[1]:= NumberQ[2]
Out[1]= True

In[2]:= NumberQ[2.2]
Out[2]= True

In[3]:= NumberQ[Rational[5, 2]]
Out[3]= True

In[4]:= NumberQ[Infinity]
Out[4]= False

In[5]:= NumberQ[Sqrt[2]]
Out[5]= False

In[6]:= NumberQ[randomvar]
Out[6]= False

In[7]:= NumberQ["hello"]
Out[7]= False