Uncaught mysqli_sql_exception: Unknown column '1660675813ZAZid' in 'field list'?

Код:

<?php 
mysqli_report(MYSQLI_REPORT_ERROR | MYSQLI_REPORT_STRICT);

    session_start();
    require_once 'bd.php';

    $code = time().'ZAZid';

    mysqli_query($con, "INSERT INTO `sasa` (`id`, `code`) VALUES (NULL, `$code`)");
    echo $code;
?>

Ошибка в SQL Запросе...