Because the sum of its proper divisors is greater than 20.
abundant
Yes 20 is an ABUNDANT number because 1+2+4+5+10=22 and that is more than 20. PS how to find and ABUNDANT number is to add up all its factors. :)
Abundent
The first five abundant numbers are 12, 18, 20, 24, and 30.
Let S be the set of the positive divisors of 20, excluding 20. S = {1, 2, 4, 5, 10} The sum of all the elements of S = 1 + 2 + 4 + 5 + 10 = 22 > 20. Therefore, 20 is an abundant number.
Let S be the set of the positive divisors of 20, excluding 20. S = {1, 2, 4, 5, 10} The sum of all the elements of S = 1 + 2 + 4 + 5 + 10 = 22 > 20. Therefore, 20 is an abundant number.
Potassium I reckon
No; 20 is an abundant number. S = {1, 2, 4, 5, 10} is the set of all positive divisors of 20, excluding itself. The sum of these divisors = 1+2+4+5+10=22 which is greater than 20. Therefore 20 is an abundant number, not a deficient number. When the sum exceeds the number, the number is abundant. When the sum equals the number, the number is perfect. When the sum is less than the number, the number is deficient.
No it is not. The closest perfect number to it is 28. The divisors of 20 are 1,2,4,5,10 those add up to more than 20 so 20 is an abundant number.
12, 18, 20, 24, 30
31
Potassium has 20 neutrons in its most abundant isotope, potassium-39.