Magento2 Minicart showing blank count

Open your root directory and open minicar‌​t.phtml.

The file path is:

app/design/frontend/{Vendor}/{themename}/Magento_Checkout/te‌​mplates/cart/minicar‌​t.phtml

You have to just replace span with below code,

    <span class="counter qty empty"
          data-bind="css: { empty: cart().summary_count == 0 }, blockLoader: isLoading">

        <!-- ko if: cart().summary_count -->
            <span class="counter-number"><!-- ko text: cart().summary_count --><!-- /ko --></span>
        <!-- /ko -->
        <!-- ko ifnot: cart().summary_count -->
            <span class="counter-number">0</span>
        <!-- /ko -->

        <span class="counter-label">
        <!-- ko if: cart().summary_count -->
            <!-- ko text: cart().summary_count --><!-- /ko -->
            <!-- ko i18n: 'items' --><!-- /ko -->
        <!-- /ko -->
        </span>
    </span>

Run command, php bin/magento setup:static-content:deploy remove var folder and check again.

Finally i got it by using below code,

<span class="counter-number"><!-- ko text: **cart().summary_count || 0** --><!-- /ko --></span>