1071

1071 is an integer as well as a year in the common era. As a number, it is an odd composite with prime factorization 3^2 × 7 × 17. It has 12 divisors: 1, 3, 7, 9, 17, 21, 51, 63, 119, 153, 357, and 1071. In Roman numerals it is MLXXI, and in binary it is 10000101111. It is divisible by 9, as the sum of its digits is 9, making it a Harshad number in base 10.

1071 commonly refers to the year AD 1071. A notable event of that year is the Battle of Manzikert, fought on August 26, 1071, in which the Seljuk Empire under Alp Arslan defeated the Byzantine Empire led by Romanos IV Diogenes. The defeat led to the loss of much of Anatolia for Byzantium and is regarded as a turning point that contributed to the gradual Turkish settlement of Asia Minor and a shift in regional power.