使用未定义的常量（整数）

This is my class. I'm using yii2. PHP 5.6. It cannot load page, it says

Use of undefined constant ‪5242880‬ - assumed '‪5242880‬'

class PicturesOfUser extends \yii\db\ActiveRecord
{
    const USER_IMG_SIZE=‪5242880‬;
}

I tested that code, and that number have some other encoded char or some other encoding, when i copiead from here, but when i rewrited that number by myself it was not showing error

const USER_IMG_SIZE = 5242880;