What is is 18 and 24 weird?

Here's some information about whether 18 and 24 are weird numbers, formatted as requested:

In number theory, a weird number is a number that is abundant (the sum of its proper divisors is greater than the number itself) but is not a [https://www.wikiwhat.page/kavramlar/perfect%20number](perfect number) or a [https://www.wikiwhat.page/kavramlar/semiperfect%20number](semiperfect number) (can't be written as the sum of some of its proper divisors).

Let's analyze 18:

• The proper divisors of 18 are 1, 2, 3, 6, and 9.
• The sum of the proper divisors is 1 + 2 + 3 + 6 + 9 = 21.
• Since 21 > 18, 18 is an [https://www.wikiwhat.page/kavramlar/abundant%20number](abundant number).
• However, 18 = 9 + 6 + 3, which means it can be written as a sum of some of its proper divisors. Therefore, 18 is a semiperfect number.
• Because it's semiperfect, 18 is not a weird number.

Now let's analyze 24:

• The proper divisors of 24 are 1, 2, 3, 4, 6, 8, and 12.
• The sum of the proper divisors is 1 + 2 + 3 + 4 + 6 + 8 + 12 = 36.
• Since 36 > 24, 24 is an [https://www.wikiwhat.page/kavramlar/abundant%20number](abundant number).
• However, 24 = 12 + 8 + 4, or 24 = 12 + 6 + 4 + 2, so 24 is a semiperfect number.
• Therefore, 24 is not a weird number.

In conclusion, neither 18 nor 24 is a weird number; they are both abundant and semiperfect. The first weird number is 70.