1317 = 3 x 439.
1317 is palindromic in base 2 (binary): 1010001000101. It is 1210210 in base 3.
1317 is the concatenation of the sixth and seventh primes. It is also the concatenation of the seventh Fibonacci number and the seventh prime.
131771317 and 713177 are both primes.
1317 is a semiprime for which the product of its digits is also a semiprime: 1 x 3 x 1 x 7 = 21 = 3 x 7.
