## Friday, 22 February 2013

### FRIDAY, 22 FEBRUARY 2013

Today is the $53^{rd}$ day of the year.

$53$ is the $16^{th}$ prime number.

$53$ is also a Sophie Germain prime. Any prime, p, is a Sophie Germain prime if $2p + 1$ is also a prime. Since $107$ is a prime, the $28^{th}$, then $53$ is a Sophie Germain prime.

The first $23$ Sophie Germain primes are:
2, 3, 5, 11, 23, 29, 41, 53, 83, 89, 113, 131, 173, 179, 191, 233, 239, 251, 281, 293, 359, 419, 431, 443, 491, 509, 593, 641, 653, 659, 683, 719, 743, 761, 809, 911, 953