Which numbers within 100 are the product of three prime numbers? Such as the title different

Which numbers within 100 are the product of three prime numbers? Such as the title different

Prime numbers within 100 are 2, 3, 5, 7, 11, 13, 17, 19
The product of three prime numbers within 100:
2*3*5=30
2*3*7=42
2*3*11=66
2*3*13=78
2*5*7=70

Which numbers within 100 are the products of three different prime numbers?
Please help the experts, please

2*3*5=30
2*3*7=42
2*3*11=66
2*3*13=78
2*5*7=70

A prime number can be divided by 2 if it is added with 3, and by 3 if it is added with 2. What is the number within 10?
Find a way!

7
7 + 3 = 10, 10 can be divided by 2
7 + 2 = 9, 9 is divisible by 3

Is the sum of 70 continuous natural numbers odd or even? Why?

70 continuous natural numbers, 35 odd and 35 even
Odd number addition of odd numbers = odd number
Even number addition = even number
Odd + even = odd
So sum is odd

Is the sum of 65 continuous natural numbers odd or even?

If there are 33 odd numbers and 32 even numbers, then the sum is odd
If there are 33 even numbers and 32 odd numbers, then the sum is even

The sum of five continuous natural numbers is 80, the smallest is () and the largest is ()

The sum of five continuous natural numbers is 80, the smallest is (14) and the largest is (18)

How many of the 2005 natural numbers from 1 to 2005 are reciprocal with 2005? I don't understand one step
In the 2005 natural numbers from 1 to 2005, how many numbers are coprime with 2005?
I figured out that it's 1600. Referring to other people's questions, the answer is 1599. I'd like to ask why we need to subtract - (say 1 is coprime with any number)

1 is neither a prime nor a composite number, so it can not be regarded as the prime factor of any number, that is to say, 1 is coprime with any number

The number coprime with any natural number is 1（

Yes, the greatest common divisor of 0 and 1 is also 1, which is coprime. There is no direct relationship between coprime and prime number. Coprime of a and B means (a, b) = 1, or the greatest common divisor of both is 1

1 and all natural numbers are coprime

That's right
Natural numbers don't include zero

How many natural numbers are there that are coprime with 100 among the natural numbers from 1 to 100

All even numbers (50) are not coprime with 100
5, 15, 25, 35, 45, 55, 65, 75, 85, 95 are not reciprocal,
∴100-50-10-1=39