Kazumasa is my best friend.

The doctor measured my pulse rate.

My heart rate increases after exercise.

Let's compare the positions of point A and point B on the number line.

In the world of mathematics, an abundant number refers to a number where the sum of its divisors is greater than the original number.

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

In math class, I learned about deficient numbers.

Amicable numbers refer to a pair of natural numbers that have a special relationship in number theory, a branch of mathematics.

What is the play count of this video?

In Japan, 4 and 9 are considered unlucky numbers.