This number is a prime.
The first edition of The Music of Primes by Marcus du Sautoy was published in 2003. [Post]
During a quarter century career as a professional stuntman from 1968 to 1993, Dick Sheppard of Gloucester, England, wrecked a total of 2003 automobiles. [Dobb]
Lance Armstrong, in 2003 (at the age of 31), became the 2nd person ever to win the Tour De France 5 times consecutively, beating the runner-up Jan Ullrich by 61 seconds. Note that 2, 5, 31, 61 and 2003 are all prime numbers. [Hartley]
The first year of the 21st century is not only prime, but has a prime concatenation of all years from 2000 through itself. I.e., 2000200120022003 is prime. [Post]
The only known prime of the form 2*10^p+p, where p and p+4 are primes. [Firoozbakht]
2003 is formed from the first two primes (2 and 3) separated by two 0's. You can get the next two primes by adding 23, then 2*3. [Merickel]
A number of years ago, Henry Nass identified some dates within the year 2003, which were represented by prime numbers, and proposed to his city councilman that the City of New York adopt a resolution commemorating these prime number dates.