Why does the html input with type “number” allow the letter ‘e’ to be entered in the field?

I have the following html5 input element:

<input type="number">

Why does this input allow for the character ‘e’ to be entered in the input field? No other alphabet character is able to be entered (as expected)

Using chrome v. 44.0.2403.107

Example below to see what I mean.

<input type="number">