180 (number) two square numbers: 12 + 6. It can be expressed as either the sum of six consecutive prime numbers: 19 + 23 + 29 + 31 + 37 + 41, or the sum of eight consecutive prime numbers: 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37. 180 is an Ulam number, which can be expressed as a sum of earlier terms in the Ulam sequence only as 177 + 3. 180 is a 61-gonal number. Half a circle has 180 degrees. Summing Euler's totient function φ("x") over the first + 24 integers gives
11 (number) century in Cologne with a number of companions, whose reported number "varies from five to eleven". A legend that Ursula died with eleven thousand virgin companions has been thought to appear from misreading "XI. M. V." (Latin abbreviation for "Eleven martyr virgins") as "Eleven thousand virgins". In the Enûma Eliš the goddess Tiamat creates eleven monsters to take revenge for the death of her husband, Apsû. 11 (number) 11 (eleven) is the natural number following 10 and preceding 12. It is the first repdigit. In English, it is the smallest positive integer requiring three syllables and the largest prime number