Is this normal?

My son fell asleep at 7pm last night, it is now 11 am the next day and he’s still sleeping. That’s 16 hours of sleep. He’s woken up a couple of times to eat and then goes right back to sleep. Is this even normal for a 10 month old?? He sleeps like this all the time, basically every day. Usually goes to bed around 9pm and won’t want to get up until 11am or noon the next day.