1559 is a prime number. It is a Sophie Germain prime because 2 x 1559 + 1 = 3119 is also prime (A005384).
Reversing the digits of 1559 produces the prime 9551. 1559 is the smallest such prime that becomes a semiprime when any single digit is removed.
1559 is the smallest prime p with 16 consecutive quadratic residues mod p.
1559 is the number of different ways to divide an 11 x 11 square into sub-squares, considering only the list of parts (A034295).
1559 is 2010202 in base 3. It is 2122 in base 9.
Source: Prime Curios!