827 is the natural number that follows 826 and precedes 828. In mathematics, 827 is a prime number. It is odd and not divisible by any integer other than 1 and itself; since 827 ≡ 3 (mod 4), it cannot be expressed as a sum of two squares. In other bases, 827 equals 0x33B in hexadecimal and 1100111011 in binary, and in Roman numerals it is DCCCXXVII. The digital root is 8 (8+2+7=17, 1+7=8). 827 is also used to designate the year AD 827, a century within the early medieval period, with activity across the Carolingian and Abbasid realms.