Number of Factors

If $x, y$ and $z$ are distinct prime numbers, then their LCM is _______

The number of multiples of a given number is

According to the property of multiples:

For $a,b\in \left\{0,1,\cdots ,9\right\}$, a two digit number $ab$ is defined for $10a+b$. A two digit number $ab$ is called a special prime if both $ab$ and $ba$ are primes. Then the total number of special primes is

It is given that the number $43361$ can be written as a product of two distinct prime numbers $p_1, p_2.$ Further, assume that there are $42900$ numbers which are less than $43361$ and are co-prime to it. Then, $p_1+p_2$ is

Mersenne numbers are numbers of the form $2^{\mathrm{n}}-1$, where $\mathrm{n} > 2$.

Marin Mersenne, a French mathematician, observed that when $\mathrm{n}=2, 3, 5$ or $7$, then $2^{\mathrm{n}}-1$, is prime.

Verify this observation.

Observe at $4=2+2, 6=3+3, 8=5+3,10=7+3 \mathrm{and} 12=7+5$. All these even numbers have been written as the sum of two prime numbers. Form a general statement based on your observations.

Observe at $4=2+2, 6=3+3, 8=5+3,10=7+3 \mathrm{and} 12=7+5$. All these even numbers have been written as the sum of two prime numbers. Determine whether or not the following even numbers can be written as the sum of exactly two primes: $2$

Observe at $4=2+2, 6=3+3, 8=5+3,10=7+3 \mathrm{and} 12=7+5$. All these even numbers have been written as the sum of two prime numbers. Determine whether or not the following even numbers can be written as the sum of exactly two primes: $128$

Observe at $4=2+2, 6=3+3, 8=5+3,10=7+3 \mathrm{and} 12=7+5$. All these even numbers have been written as the sum of two prime numbers.

Determine whether or not the following even numbers can be written as the sum of exactly two primes: $98$

Observe at $4=2+2, 6=3+3, 8=5+3, 10=7+3 \mathrm{and} 12=7+5$. All these even numbers have been written as the sum of two prime numbers. Determine whether or not the following even numbers can be written as the sum of exactly two primes. $30$

Observe at $4=2+2, 6=3+3, 8=5+3,10 =7+3 \mathrm{and} 12=7+5$. All these even numbers have been written as the sum of two prime numbers. Show that $14, 16, 18$ and $20$ can also be written as the sum of exactly two prime numbers.

Which numbers are Prime numbers between $70$ and $80$?

Which number is neither Prime nor Composite?

Which number is smallest even Prime number?

Write the prime numbers from the following:

$27 29 37 47 49 39$

Write the prime numbers from the following:

$18 41 23 17 19 27$

Write the prime numbers from the following:

$10 5 25 35 42 33$

Write the prime numbers from the following:

$2 9 11 13 16 21$

Write the prime numbers from the following:

$12 8 5 7 6 3$