111 (number)

111 (One hundred [and] eleven) is the natural number following 110 and preceding 112.

In mathematics

111 is a perfect totient number.^[1]

111 is R₃ or the second repunit, a number like 11, 111, or 1111 that consists of repeated units, or 1's. It equals 3 × 37, therefore all triplets (numbers like 222 or 777) in base ten are of the form 3n × 37. As a repunit, it also follows that 111 is a palindromic number.

All triplets in all bases are multiples of 111 in that base, therefore the number represented by 111 in a particular base is the only triplet that can ever be prime. 111 is not prime in base ten, but is prime in base two, where 111₂ = 7₁₀. It is also prime in these other bases up to 128: 3, 5, 6, 8, 12, 14, 15, 17, 20, 21, 24, 27, 33, 38, 41, 50, 54, 57, 59, 62, 66, 69, 71, 75, 77, 78, 80, 89, 90, 99, 101, 105, 110, 111, 117, 119 (sequence A002384 in the OEIS)

In base 18, the number 111 is 7³ (= 343₁₀) which is the only base where 111 is a perfect power.

The smallest magic square using only 1 and prime numbers has a magic constant of 111:

A six-by-six magic square using the numbers 1 through 36 also has a magic constant of 111:

(The square has this magic constant because 1 + 2 + 3 + ... + 34 + 35 + 36 = 666, and 666 / 6 = 111).

111 is also the magic constant of the n-Queens Problem for n = 6.^[2] It is also an nonagonal number.^[3]

In base 10, it is a Harshad number.^[4]

Nelson

The number 111 is sometimes called "a Nelson" after Admiral Nelson, who allegedly only had "One Eye, One Arm, One Leg" near the end of his life. This is in fact inaccurate - Nelson never lost a leg. Alternate meanings include "One Eye, One Arm, One Ambition" and "One Eye, One Arm, One Arsehole".

It is particularly known as a score in cricket. A score of 111 or multiples thereof (222 = "double nelson", 333 = "triple nelson" and so on) is considered unlucky by some in English cricket: most famously by the international umpire David Shepherd, who had a whole retinue of peculiar mannerisms - hops, shuffles, jiggles and so on - that he would indulge in if the score was ever a "Nelson" multiple. Particularly if the number of wickets also matched - 111/1, 222/2 etc.

In other fields

111 is also:

• The atomic number of the element roentgenium (Rg).
• The chemical compound 1,1,1-Trichloroethane is a chlorinated hydrocarbon that was used as an industrial solvent with a trade name "Solvent 111".
• The emergency telephone number in New Zealand; see 111 (emergency telephone number).
• A non-emergency medical public helpline operating in England and Scotland; see NHS 111.
• It is the lowest positive integer requiring six syllables to name in American English, or seven syllables (including "and") in Canadian and British English.
• Occasionally it is referred to as "eleventy-one", as read in The Fellowship of the Ring by J.R.R. Tolkien.^[5]
• Great Western Railway Pacific locomotive 4-6-2 111 The Great Bear was designed by George Jackson Churchward in 1908. The locomotive was rebuilt into a Castle Class engine in 1924 and was later renamed Viscount Churchill. The numbers 111 remained until she was scrapped in July 1953.

See also

• List of highways numbered 111

References

• Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 134

External links

Wikimedia Commons has media related to 111 (number).

• The Number 111 at the VirtueScience Database of Number Correlations
• The 111 Experience of J'lahn