Question

A number is called a perfect number because the sum of its factors=twice the number. But what do we call a number , when the sum of its factors = thrice the number. Sum of the factors of 120 = 360

Answer 1

Dear Student,

There is a term called "k+1 Perfect" number - A number whose sum of divisors is k times the number itself.

Hence for 120- sum of divisors excluding the number 120=1+2+3+4+5+6+8+10+12+15+20+24+30+40+60
Hence sum of divisors=240 which is 2 times the number 120

Thus the number 120=(k+1) perfect= (2+1) perfect that is 3-Perfect number.

Regards,