400 (number) sum of twelve consecutive primes (13 + 17 + 19 + 23 + 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59) 413 = 7 × 59, Mertens function returns 0, self number 414 = 2 × 3 × 23, Mertens function returns 0, nontotient, Harshad number 415 = 5 × 83, 416 = 2 × 13 417 = 3 × 139 418 = 2 × 11 × 19, sphenic number, A prime number, Sophie Germain prime, Chen prime, Eisenstein prime with no imaginary part, highly cototient number, Mertens function returns 0 A prime
11 (number) 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 with a single-morpheme name. Eleven derives from the Old English ' which is first attested in Bede's late 9th-century "Ecclesiastical History of the English People". It has cognates in every Germanic language (for example, German "elf"), whose Proto-Germanic ancestor has been reconstructed as *"ainalifa-", from the prefix *"aina-" (adjectival "one") and suffix *"-lifa-" of uncertain meaning. It is sometimes compared with the Lithuanian ', although ""