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Numbers under 100 with three different prime factors are 30, 42, 66, 70 and 78.
Numbers under 100 with three different prime factors, at least one of which has multiplicity > 1 are 8, 12, 18, 20, 27, 28, 44, 45, 50, 52, 63, 68, 75, 76, 92, 98 and 99.
They are:
8, 12, 18, 20, 27,
28, 30, 42, 44, 45,
50, 52, 63, 66, 68,
70, 75, 76, 78, 92,
98, 99.
There are some that have more than 3 - which means that they do have 3.
[That last part is like the old riddle: how many months have 28 days - and the answer is all of them. Eleven have more than 28, but they do have 28.]
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How many number under 10 have 2 factors?
There are 4 prime numbers under ten.
What numbers under 100 have 3 different prime factors?
30, 42, 66, 70 and 78.
How many prime numbers are there under 50?
There are 15 prime numbers less than 50.
Are prime numbers is closed under multilplication?
By definition, a product of two primes has atwo factors (other than 1 and itself) and so it cannot be prime. So the set is not closed.
Are prime numbers closed under subtration?
No.
What are the prime numbers under 100 that have 2 and 7 as factors?
There are no prime numbers anywhere that are divisible by 2 and 7.
How many number under 10 have 2 factors?
There are 4 prime numbers under ten.
Prime numbers under 6?
Prime Numbers under 6 are 2,3,5
What numbers under 100 have 3 different prime factors?
30, 42, 66, 70 and 78.
How many prime numbers are under 140?
There are 34 prime numbers under 140.
What are all the prime numbers under 16?
The prime numbers under 16 are 2,3,5,7,11 & 13.
What is the prime factorization of numbers 1 to 200?
If you look at the related question, "What are the prime factors of the numbers from 1 to 200?" (provided in the link below), take the prime numbers, and show them with multiplication signs between them, then you will have the prime factorization. Examples: The prime factors of 15 are 3 and 5. Therefore, the prime factorization is 3 x 5. The prime factors of 42 are 2, 3, and 7. Therefore, the prime factorization is 2 x 3 x 7. The prime factors of 64 are 2, 2, 2, 2, 2, and 2. Therefore, the prime factorization is 2 x 2 x 2 x 2 x 2 x 2. If you want the prime factorization of a specific number, it is sometimes listed under questions of the form, "What are the prime factors of __?" or "What are the factors of __?" or "What are the factors and prime factors of __?"
What numbers have exactly 4 factors under 100?
Any product of 2 prime numbers will have 4 factors. Any prime number to the 3rd power will have 4 factors.6, 8, 10, 14, 15, 21, 22, 26, 27, 33, 34, 35, 38, 39, 46, 51, 55, 57, 58, 62, 65, 69, 74, 77, 82, 85, 86, 87, 91, 93, 94, 95
What are 2 numbers under 50 that have exactly 3 factors?
The prime squares, like 4, 9, 25 and 49
Multiples of Prime numbers under 20?
All the numbers from 2 to 19 are multiples of prime numbers.
How many prime numbers are there till 1000?
168 prime numbers under 1000.
Are prime numbers closed under addition?
no, not all prime numbers are closed under addition. why? because, when you add 2 prime numbers you will not always get a prime number. example: 5+3= 8 5 and 3 are prime numbers but their sum is 8 which is a composite number..
