Numbers 160-169

A page of the Numeropedia - the Special Encyclopedia of Numbers

1  - 10 - 100  - 1000 - 10,000 - 100,000 - 1M - 10M - 100M1B10B - 100B - 1T - 10T - 100T - 1Q - ...

160

[Gov.]  Within a “leave year”, a U.S. government employee earns 4 hours (for 0-3 working years), 6 hours (3-15 years) or 8 hours (over 15 years) of “annual leave” for each of 26 leave periods of 2 weeks, respectively, for a total of 104, 160 (156 plus 4 extra hours for the last pay period within the calendar year) or 208 hours of “annual leave”, respectively.

[EECS]  160(W, KW or MW) is one of standard numerical values for resistors (of tolerance class 5%).

[History]  The Winchester Mystery House in San Jose, Silicon Valley, California is an unfinished 160-room Victorian mansion with 47 fireplaces, which was built continuously in 38 years (1884 to 5 September 1922).

[Math.]  Each internal angle of a regular 18-sided polygon (octadecagon) is 160o.

[Math.]  160 = 23+33+53, sum of cubes of the first 3 prime numbers.

[Math.]  Three square numbers using the same digits: 1602 = 25600, 2452 = 60025 and 2502 = 62500.

[Measure]  The number of square rods in an acre.

U.S. customary units for area measures: 1 acre = 160 square rods = 4,840 square yards = 43,560 square feet = 6,272,640 square inches = 4046.8564224 m2 & 1 square mile (1 section) = 640 acres = 2,589,988.11 m2 = 2.59 km2 = 259 hectares & 1 hectare = 2.471 acres = 10,000 m2 & 1 township = 36 square miles.

[Measure]  The number of fluidounces in a gallon.

British imperial units for dry and liquid measures: 1 bushel = 4 pecks = 8 gallons = 32 quarts = 64 pints = 256 gills = 1280 fluidounces = 36.368736 liters.

[Sport]  The width (feet) of an American football field is 531/3 yards.

[Sport]  The weight range for the Middleweight boxing class is 154-160 lbs. The weight range for the Super Middleweight boxing class is 160-168 lbs.

[Tech.]  The hash functions recommended/approved by NIST to replace SHA-1, which outputs 160 bits hash: SHA-512, SHA-384, SHA-256 and SHA-224. All 3-digit number indicates the number of output bits.

[Tech.]  Automobile Tire’s Speed Rating

 Tire Rating L M N P Q R S Max. Speed (mph) Max. Speed (kph) 75 120 81 130 87 140 93 150 100 160 106 170 112 180 Tire Rating T U H V W Y Max. Speed (mph) Max. Speed (kph) 118 190 124 200 130 210 149 240 168 270 186 300

161

[Math.]  1613 = 4173281 = (41+7+32+81)3.

[Geology]  The length of the man-made Suez Canal is 161.9 kilometers = 100.6 miles.

162

[Math.]  Each internal angle of a regular 20-sided polygon (icosagon) is 162o.

[Sport]  The number of games played in a full professional baseball season (excluding the play-offs) by a team in North America, (American League AL and National League NL).

[World]  The ISO country code for Christmas Island. (ISO-3166)

163

[Math.]  A prime number.

[Math.]  The only integer in the Ramanujan constant e^(p´1631/2) = 262,537,412,640,768,743.999999999999250072…, which is a transcendental number (i.e., not a root of any polynomial equation with integer coefficients)extremely close to the integer 262,537,412,640,768,744.

[Math.]  (e^(p´1631/2)–744)1/3 = 640,319.9999999999999999999999993903… is a transcendental number (i.e., not a root of any polynomial equation with integer coefficients)extremely close to the integer 640,320.

[Math.]  The largest square-free number that the imaginary quadratic field Q((–k)1/2) has class number h(–163) = 1; i.e. the field is a UFD (unique factorization domain).

164

[Game]  The highest possible score of a word in the Scrabble game is the word “Quartzy”: playing across triple-word square with “z” on a double-letter square and a premium of 50 for using all 7 letters on the rack.

[Tech.]  Volvo’s numbered series: 140 (142, 144, 145), 164, 240 (242, 244, 245), 260 (262, 264, 265), 340 (343, 345), 360, 440, 460, 480, 740, 760, 780, 850, 940 and 960. Digit 0 is replaced by the number of doors.

165

[Math.]  Each internal angle of a regular 24-sided polygon is 165o.

[Math.]  Two consecutive sums of consecutive numbers:

25+26+…+29+30 = 31+32+…+34+35 = 165.

[Math.]  Inserting 72 between 2 digits 2 in the square number 225 = 152 and repeatedly inserting numbers 72 between the digits 7 and 2 yields other squares 27225 = 1652, 2772225  = 16652, 277722225 = 166652, 27777222225 = 1666652, 2777772222225 = 16666652

[Math.]  0165×34 = 5,610.

[Tech.]  Automobile tires used in the U.S. have tire section width of 145, 155, 165, 175, 185, 195, 205, 215, 225, 235, 245 or 255 (millimeters).

166

[Math.]  166,500,333 = 1663+5003+3333.

[Phone]  The emergency telephone number dialing within Philippines (and 117).

[World]  The ISO country code for Cocos (Keeling) Islands. (ISO-3166)

167

[Math.]  1674 = 777,796,321. The smallest number whose 4th power starts with 4 identical digit.

168

[Calendar]  The number of hours in a week.

1 week = 7 days = 168 hours = 10,080 minutes = 604,800 seconds.

[Game]  The total number of dots of all the tiles in a double-6 set of dominoes.

[Math.]  Each internal angle of a regular 30-sided polygon (triacontagon) is 168o.

[Math.]  The number of prime numbers less than 1000.

[Math.]  144,648 = 861×168 = 492×294.

[Sport]  The weight range for the Super Middleweight boxing class is 160-168 lbs. The weight range for the Light Heavyweight boxing class is 168-175 lbs.

[Tech.]  Automobile Tire’s Speed Rating

 Tire Rating L M N P Q R S Max. Speed (mph) Max. Speed (kph) 75 120 81 130 87 140 93 150 100 160 106 170 112 180 Tire Rating T U H V W Y Max. Speed (mph) Max. Speed (kph) 118 190 124 200 130 210 149 240 168 270 186 300

169

[Geology]  Tonga is an archipelago of 169 islands (36 inhabited).

[Math.]  Reversible numbers and their squares: 132 = 169 and 312 = 961 = 312.

[Math.]  Three square numbers using the same digits: 132 = 169, 142 = 196 and 312 = 961.

[Math.]  Squares of 2 consecutive numbers that use the same digits: 132 = 169 and 142 = 196. Others: 1572 & 1582 and 9132 & 9142.

[Math.]   162,409 = 169×961 = 4032 = 13×13×31×31.

[Math.]  169 = (16+9)+(16×9).

[Math.]  The 3rd square number that is the sum of squares of 2 consecutive numbers: 28561 = 1692 = 1192+1202. Each root number in the series is 6 times the previous root number minus the earlier root number:  1, 52, 292, 1692, 9852

Or in other words:  (119, 120, 169) is the 3rd Pythagorean triple (lengths of 3 sides of a right triangle), where 2 sides are consecutive integers.

[Math.]  The first Markov numbers are 1, 2, 5, 13, 29, 34, 89, 169, 194, 233...

160-169

[Library]  Numbers 100-199 are the first 3 digits in Dewey Decimal Classification System call numbers for library books in Philosophy, Psychology and Ethics… Numbers 160-169 are for books in Logic.

100-199

[Education] The numbers commonly assigned for upper level undergraduate (last 2 years, junior and senior) courses in most U.S. universities and colleges.