No. The data is not 'backed up by Apple'.
IF you were signed into your Apple account, AND you had already enabled Backups to iCloud, AND you had sufficient iCloud storage space available, your phone would have backed up every night when it was in standby and connected to power and WiFi.
After erasing the phone, when it goes through its startup process, you will be prompted to transfer your data from another device or restoring from a backup. If you have a backup, you can restore from that. If you did not have a backup either in iCloud or made in iTunes on your computer, your data is gone.