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Perfect Numbers
Last updated at July 8, 2025 by Teachoo
Factors and Multiples
Class 6 (Ganit Prakash)
Chapter 5 Class 6 - Prime Time (Ganita Prakash)
Transcript
Perfect numbers If Sum of all factors is equal to twice the number, then number is called a perfect number For 6 Factors of 6 are 1, 2, 3, 6 Sum of factors = 1 + 2 + 3 + 6 = 12 Since 12 = 2 × 6 ∴ Sum of factors is equal to twice the number So, 6 is a perfect number For 28 Factors of 28 are 1, 2, 4, 7, 14, 28 Sum of factors = 1 + 2 + 4 + 7 + 14 + 28 = 56 Since 56 = 2 × 28 ∴ Sum of factors is equal to twice the number So, 28 is a perfect number For 10 Factors of 10 are 1, 2, 5, 10 Sum of factors = 1 + 2 + 5 + 10 = 18 Since 18 is not twice of 10 So, 10 is not a perfect number First 10 perfect numbers are 6 28 496 8128 33550336 8589869056 137438691328 2305843008139952128 2658455991569831744654692615953842176 191561942608236107294793378084303638130997321548169216
