1109
This number is a prime.
The smallest 4-digit prime n such that p1 = 2n+3, p2 = 4n+5, and p3 = 6n+7 are all prime. [Russo]
The smallest invertible prime whose concatenated pair form
a strobogrammatic prime (11096011). The sequence begins
1109, 1699, 6689, 6691, 6991, ....
The only emirp derived from a two-digit prime by inserting
the sum of its digits in-between. [Loungrides]
In the ISO 860 date format the terrorist attack against New York on day "nine eleven" is written as 1109. [Petersson]
In Hebrew, the gematria value of משיח בן דוד ("Messiah, the
son of David") is 424. The first occurrence of 424 in pi
begins from position 1109, and is followed by 541 (the
100th prime number and the gematria value of "Israel").
1109 is the 186th prime number, and the first occurrence of
186 in π begins from position 424. [Slattery]