It is simply: 3 times 7 = 21
As a product of its prime factors: 3*7 = 21
21 as a product of its prime factors is 1 X 3 X 7.
It is 3 time 7 = 21
It is: 3*7 = 21
As a product of its prime factors: 3*3*7*7 = 441 Its square root is 21 or as 3*7 as the product of its prime factors
It is when the prime factors of whole number are multiplied together that they equal that number. For example the prime factors of 21 are 3 and 7 so 3*7 = 21
2²×3×5
1, 3, 7, 21 3 and 7 are prime.
The factors of 21 are: 1 3 7 21 The prime factors are: 3 and 7
factors of 21: 3, 7 prime factors of 21: 3, 7
The factors are 1, 3, 7 and 21. 3 and 7 are prime.
18 has prime factors 3 & 2 whereas 21 has prime factors 3 & 7.