Sub a()
Dim v As Variant, i
Do
v = Application.InputBox("Entrez un nombre entier :", "Numéro", CStr(v), Type:=2)
If v = False Then Exit Sub
For i = 1 To Len(v)
If Not IsNumeric(Mid(v, i, 1)) Then Exit For
Next
Loop While i <= Len(v) Or v = ""
[A1] = v
End Sub