You should know the first ten prime numbers
7 = 7x1, 2 factors so it’s prime ✅
8 = 8x1, 2x4, 4 factors do it’s not prime ❌
11 =11x1, 2 factors so it’s prime ✅
1 = 1 x1 only one factor so it’s not prime❌
A prime number has 2 and only 2 factors.
Here are the first ten prime numbers
2, 3, 5, 7 there are four in the units
11, 13, 17, 19 there are four in the tens
23, 29. there are two in the twenties, then they become more and more rare.
All other numbers called composite numbers are made from prime numbers.
5x7= 35 35 is not prime but a composite number made from primes
3x5x7= 105 105 is not prime but a composite number made from primes.
2 is the only even prime number.
A collaborative computational effort has uncovered the longest known prime number.
At over 23 million digits long, the new number has been given the name M77232917 for short.
The next largest prime number will attract the prize of $3000 as they’re needed for computer codes and security matters.