513 = 33 x 19.
513 is 1000000001 in base 2 and 1001 in base 8. It is 20001 in base 4 and 201 in base 16.
513 is a sum of two positive cubes: 513 = 83 + 13.
513 appears in the sequence generated when you start with 1 and repeatedly reverse the digits and add 16 to get the next term.
513 are the first three digits in the Dewey Decimal Classification System call numbers for library books in arithmetic.
