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21: 3, 7
22: 2, 11
23: 23
24: 2, 3
25: 5
26: 2, 13
27: 3
28: 2, 7
29: 29
30: 2, 3, 5
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∙ 11y ago
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What are prime numbers of 21?
factors of 21: 3, 7 prime factors of 21: 3, 7
How many prime numbers are there in 21?
21 has two prime factors.
Are all odd numbers prime why or why not?
NO. Not all odd numbers are prime like 9, 15, 21, 27,... because they have other factors aside from 1 and itself.
What 2 prime numbers are factors of 21?
3 and 7
Can odd numbers be composite?
If an odd number has more than two factors then it is a composite number but if it has only two factors then it is a prime number. Although all prime numbers are odd except for 2 many more odd numbers are composite numbers having more than two factors as for example 21 is an odd number whose factors are 1, 3, 7 and 21.
Why do all odd numbers have more prime factors?
They don't. 21 has two prime factors. 42 has three prime factors.
What are prime numbers of 21?
factors of 21: 3, 7 prime factors of 21: 3, 7
How many prime numbers are there in 21?
21 has two prime factors.
What are the prime numbers for 21?
The prime factors of 21 are 3 x 7.
Are all odd numbers prime why or why not?
NO. Not all odd numbers are prime like 9, 15, 21, 27,... because they have other factors aside from 1 and itself.
What are the prime numbers from 1 to 21?
1isn't prime or composite. So 2,3,5,7,11,13,17,19 are all prime because there only factors are 1 and itself.
What are two numbers that have no common factors?
40 and 21 have no common prime factors
What 2 prime numbers are factors of 21?
3 and 7
Are all odd numbers prime numbers?
No because 2 is an even number which is also a Prime number that has only two factors which are itself and one.
What is the LCM of 28 and 21?
To determine the least common multiple of two numbers, determine the prime factors of both number. Then, determine the prime factors they have in common. Multiply all their prime factors together (in other words, multiply both numbers together) and divide by the prime factors they have in common (in other words, their greatest common factor). The prime factors of 21 are 3 and 7. The prime factors of 28 are 2, 2, and 7. The prime factors in common are a single 7. Therefore, the lowest common multiple is 21 x 28 ÷ 7 = 84
Is 21 and 27 prime and composite numbers?
A prime number has exactly two factors, 1 and the number itself. The factors of 21 are 1, 3, 7, and 21, and the factors of 27 are 1, 3, 9, and 27. Since 21 and 27 have more than 2 factors, they are composite numbers.
What does common prime factors mean?
When two or more numbers have one or more of the same primes as factors, those prime factors are called common prime factors. For example, the prime factors of 6 are 2 and 3, and the prime factors of 21 are 3 and 7, so 3 is a common prime factor of 6 and 21.
