1619
This number is a prime.
A prime whose cube can be expressed as the sum of three prime squares in two different ways, i.e., 16193 is 32 + 249672 + 601692 and 32 + 281632 + 587412. [Rivera]
Kepler's 3rd Law of planetary motion wasn't published until 1619.
The smallest nonprime-digit emirp that remains a
nonprime-digit emirp when each digit is replaced by its
complement (9491). Note that it is also the smallest
nonprime-digit emirp that remains an emirp when sandwiched
between a pair of prime digits (316193) and that the sum of
digits is prime in all cases. [Beedassy]
Exactly half of the first 3238 positive integers (1619)
contain no twos. [Gaydos]
1619 is the 256th prime. If you square the number formed from the first two digits in ascending order, namely 16, you get 256. [Missailidis]