How to stop the letter e being accepted in number input field.

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HTML

PHP

I have a number of inputs which are purely integers namely 0 to 54.
My code for input is thus

<td> <input id="P1HC" name="P1HC" type="number" min="0" max="54" size= "1"  pattern="^[1-9]$"  value="<?php echo $_SESSION["HC1"]; ?>"> </td>

However, I can still type 'e' into the input. It will not accept any other letter or characters other than 0 to 9 or e.
Also I can type in numbers greater than 54 why?

Any ideas?
Plan to validate in PHP server side but wanted to check at the user side first.

What I have tried:

Also tried adding

onchange = "check(this)"

with javascript of

function check(that) {
        var StringInput = that.value;
    if (!/^[1-9]*$/g.test(StringInput)) {
        alert("You have entered invalid characters");
        that.value = "";
        that.focus();
        return false;
    }
    }

Still did not work.