626 = 2 x 313. It is the smallest multidigit, palindromic, two-sided semiprime.
626 has a representation as a sum of two squares: 626 = 12 + 252.
626 is a palindrome in base 5 (10001), base 10 (626), and base 16 (272).
626 is the sum of two nonzero fourth powers: 626 = 54 + 14.
Source: Prime Curios!