The two prime numbers immediately following 17 are 19 and 23.
47 x 43 = 2021
It is: 47*53 = 2491
47 x 53 = 2491
The number 356 is not prime. You should immediately notice that it is an even number, divisible by two, therefore it cannot be prime. Only odd numbers can be prime.
Eliminate the even numbers. Eliminate the odd numbers with more than two factors. 41 is left.
So we eliminate prime numbers. Note that the number 1 is neither prime nor composite. We have left:4689101214151618202122242526272830323334353638394042444546484950515254555657586062636465666869707274757677788081828485868788909192939495969899100
The two prime numbers immediately following 17 are 19 and 23.
Negative numbers Even numbers greater than two Zero and one
It is: 59*61 = 3599
23 and 29 are the prime numbers between 20 and 30.The two prime numbers between 20 and 30 are 23 and 29.23, 29All the prime numbers will be odd so you can immediately eliminate 22, 24, 26 and 2821 = 3x7 so that 's not prime25 = 5x5, so that's not prime27 = 3x3x3 so that's not prime
47 x 43 = 2021
It is: 47*53 = 2491
47 x 53 = 2491
The number 356 is not prime. You should immediately notice that it is an even number, divisible by two, therefore it cannot be prime. Only odd numbers can be prime.
Work It Out By Drawing A Grid, Eliminate the 2 Times Tables, Then 3, Then 5, Then 7, Then 11, Then 13, And All The Primes, And Your Be Left With The Higher Prime Numbers :D
If it's even and greater than two, it's not prime. If you know the divisibility rules, you can eliminate 3 through 10 as factors. Through trial and error, you can eliminate 11, 13, 17 and 19 and so on until you get bored. That leaves numbers like 1849 which looks prime but is actually the product of 43 and 43. For large numbers like that, Google "list of prime numbers" and click on the first 10000 primes. That will let you know for certain.