Factors: 42 = 2*3*7, 63 = 3*3*7, 105 = 3*5*7. Common factors are 3 and 7. HCF = 3 * 7 = 21.
गुणनखंड: 42 = 2*3*7, 63 = 3*3*7, 105 = 3*5*7। सामान्य गुणनखंड 3 और 7 हैं। HCF = 3 * 7 = 21।