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Art of Numbers!!

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Written by   35
2 years ago

Magic: 1

Hey!! Do you have any idea about amicable numbers? Just keep in mind 220 and 284 are amicable or you can say friend numbers!! How? That should be the big question. I am now explaining it to you.

See, the factors of 220 are : 1,2,4,5,10,11,20,22,44,55,110

Now if you add them together the summation becomes 284!!

Again, the factors of 284 are: 1,2,4,71,142

If you add them together the summation becomes 220!! Isn't it interesting?

Magic: 2

Now, do you know what perfect numbers are?

These are such numbers, the sum of those factors (except the number itself), is equal to the nunber It's elves!!

Example : 6,28,496

The factors of 6 are 1,2,3 and 6. Now if you add 1,2 and 3 the summation becomes 6!!

Again, the factors of 28 are 1,2,4,7,14,28. Niw if you add the factors except 28 it becomes 28!! Same in the case of 496.

Note :

Always remember the sequence of prime numbers from 1 to 100. This is

4422-322-321, Total = 25 prime numbers.

Magic: 3

Do you know how to recognise a prime numbers??

Let, p be a given number and let n be the smallest counting number such that n^2 >=p. Now test whether p is divisible by any of the prime numbers less than or equal to n. If yes, then p is not Prime number, otherwise p is prime.

Example : let 811. We know that (30)^2 > 811. Now prime numbers less than 30 are 2,3,5,7,11,13,17,19,23,29. Clearly none of this numbers divides 811.

Therefor, 811 is a prime number. Try 137 yourself!!

Again, let 437. We know that (21)^2 > 437. Now prime numbers less than 21 are 2,3,5,7,11,13,17,19. Clearly 437 is divisible by 19. So 437 is not a prime!! Interesting, isn't it??


There is a arithmetic sequence of five numbers!! Can you imagine?

See, 5,11,17,13,29!! The difference is 6 every time? Do you now it before?

So, that's all for today. Play with numbers. It will keep Your brain so active and fresh.

Stay tuned. Happy Numbering. 🧠✍

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Written by   35
2 years ago
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