About the Number 21,000 (twenty-one thousand)

The DJIA closed above 21,000 on 1 March 2017 (Future Day 2017). It took 24 days for the DJIA to increase from 20,000 to 21,000.

MathBabbler Number Analyst (MBNA) output:
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21000 is natural, counting, whole, integer
21000 is even (not odd)
21000 proper divisors are: 1,2,3,4,5,6,7,8,10,12,14,15,20,21,24,25,28,
                           30,35,40,42,50,56,60,70,75,84,100,105,120,
                           125,140,150,168,175,200,210,250,280,300,350,
                           375,420,500,525,600,700,750,840,875,1000,1050,
                           1400,1500,1750,2100,2625,3000,3500,4200,5250,
                           7000,10500,
21000 has 63 proper divisors
21000 is abundant (sum of divisors is 53880; ratio: 2.56571)
21000 is unhappy
21000 is not a Squarefree Number: 4,25,100,
21000 is Harshad (Niven) number
21000 is composite (not prime)
21000 has the prime factors: 2*2*2*3*5*5*5*7 (sum=31)
21000 is a 7-smooth number
21000 in octal is 051010
21000 in hexadecimal is 0x5208
21000 in binary is 101001000001000 (is evil)
21000 nearest square numbers: -264...25 (20736...21025 [145])
sqrt(21000) = 144.914
ln(21000) = 9.95228
log(21000) = 4.32222
21000 is an apocalyptic power (2^21000 contains 666)
21000! is inf
21000 is 6684.51 Pi years
21000 is 1050 scoreyears
21000 is 5251^2 - 5249^2 and 2 * (5251 + 5249)
21000 is a multiple of 1 & it contains a 1 (A011531)
21000 is a multiple of 2 & it contains a 2 (A121022)
21000 is a multiple of 10 & it contains a 10 (A121030)
21000 is a multiple of 21 & it contains a 21
21000 is a multiple of 100 & it contains a 100
21000 is a multiple of 210 & it contains a 210
21000 is a multiple of 1000 & it contains a 1000
21000 is a multiple of 2100 & it contains a 2100
                         ______
21000 reciprocal is 0.000047619
remainders: 
1,10,100,1000,10000,16000,13000,4000,19000,1000

Creator: Gerald Thurman [gthurman@gmail.com]
Created: 02 March 2017

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This work is licensed under a Creative Commons Attribution 3.0 United States License.