In mathematics, a perfect number refers to a number where the sum of its divisors, excluding the number itself, equals the number.

This fish is completely farmed, and no capture is done in the natural environment.

He is immersed in the study of panmagic squares.

He is a perfectionist, and his approach to work is very strict.

He has a deep interest in archaeology.

He understands the importance of learning.

He is majoring in psychology.

Gaku is my best friend.

Natural language understanding is an important field of artificial intelligence.

The depressed cowry lives quietly at the bottom of the sea.