23 is a prime number from 1-100. 23 has two factors, 1 and 23. 23 is said to also be one of the numbers that when you add up its digits, you get a prime number. It is the ninth prime number, and the ninth prime number from 1-100.
Proofs
— 23 can be divided by 1
- — 23 can be divided by 23
- 23 can divide itself
Relationships with other odd numbers
The numbers before
- The previous odd number, 21, is not a prime number. It is divisible by 3 and 7.
- The odd number previous to 21 is 19. 19 is a prime number.
- 19 and 23 are four numbers apart; therefore, they are cousin primes.
- The odd number previous to 19 is 17. 17 is a prime number.
- 17 and 23 are six numbers apart; therefore, they are sexy primes.
The numbers after
- The next odd number, 25, is not a prime number. It is a square number, being 52 = 25.
- 27, the odd number following 25, is not a prime number. It is a cube number, being 33 = 27.
- 29, the odd number following 27, is a prime number.
- 23 and 29 are six numbers apart; therefore, they are sexy primes.
- Due to the fact that 23 is not part of any twin numbers, it is considered an isolated prime.