233 (number) explained

Number:	233
Prime:	yes

233 (two hundred [and] thirty-three) is the natural number following 232 and preceding 234.

Additionally:

• 233 is a prime number^[1]
• 233 is a Sophie Germain prime,^[2] a Pillai prime,^[3] and a Ramanujan prime^[4]
• It is a Fibonacci number,^[5] one of the Fibonacci primes^[6]
• There are exactly 233 maximal planar graphs with ten vertices,^[7] and 233 connected topological spaces with four points^[8]

Notes and References

1. The prime numbers.
2. Sophie Germain primes p: 2p+1 is also prime.
3. Pillai primes.
4. Ramanujan primes.
5. Fibonacci numbers.
6. Prime Fibonacci numbers.
7. Number of simplicial polyhedra with n nodes.
8. Number of connected topologies on n labeled points.