563

563 is a natural number that follows 562 and precedes 564.

In mathematics, 563 is prime. It is the 103rd prime number. It is odd and congruent to 3 modulo 4, which implies it cannot be written as a sum of two squares.

In numeral representations, 563 is written as DLXIII in Roman numerals. In binary it is 1000110011.

In the calendar, the year 563 CE falls in the early medieval period. Notable events include Saint Columba establishing a monastery on the island of Iona, which became a center of Celtic Christian activity.

In modern telecommunication, 563 is the area code for parts of eastern Iowa in the United States.