11 is a prime number from 1-100. 11 is prime because it only has two factors, 1 and 11. This has a pattern because when you add the digits of 11, you still get a prime number, 2, the same for 29 (29, 11, 2), 41, and many more. It is the fifth prime number, and the fifth prime number from 1-100.
Proofs
- 1 can be divided by 11
- 2 - 10 cannot be divided by 11
- 11 can be divided by itself
- Therefore 11 has 2 factors
Relationship with other odd numbers
The numbers before
- The previous odd number, 9, is a square number.
- The odd number previous to 9 is 7. 7 is a prime number.
- 7 and 11 are four numbers apart; therefore, they are cousin primes.
- The odd number previous to 7 is 5. 5 is a prime number.
- 5 and 11 are six numbers apart; therefore, they are sexy primes.
The numbers after
- The next odd number, 13, is a prime number.
- There are no odd numbers between 11, 13. As a result, they are twin primes.
- 15, the odd number following 13, is not a prime number. It is divisible by 3 and 5.
- 17, the odd number following 15, is a prime number.
- 11 and 17 are six numbers apart; therefore, they are sexy primes.