1161

1161 is a natural number and a year designation. As a number, it is odd and composite, with prime factorization 3^3 × 43. Its positive divisors are 1, 3, 9, 27, 43, 129, 387, and 1161. The sum of its digits is 9, so 1161 is divisible by 9 (1161 ÷ 9 = 129), making it a Harshad number in base 10. In different numeral systems, 1161 is represented as 0x489 in hexadecimal and 10010001001 in binary. In Roman numerals it is written as MCLXI. It lies between the squares 34^2 = 1156 and 35^2 = 1225, being five units above 34^2.

As a year, 1161 CE falls in the Middle Ages, specifically the 12th century. It would have been part of the broader historical context of medieval Europe, the Crusades era in some regions, and developments in neighboring regions such as the Byzantine Empire and various Islamic and Asian polities. Specific events in the year are regionally diverse and not uniform across the world, reflecting the fragmented and localized nature of historical records from that period.

In summary, 1161 is a composite number with characteristic factors and standard base representations, and it also denotes a year in the 12th century within the common historical framework of the Middle Ages.