This nBAB was created on the 75th anniversary of the ratification of the 21st Amendment. The 21st Amendment repealed the 18th Amendment (Prohibition).
MathBabbler Number Analyst (MBNA) output: ========================================= 21 is a natural, whole, integer 21 is odd 21 proper divisors are: 1,3,7, 21 is deficient (sum of divisors is 11) 21 is unhappy 21 is a Harshad number 21 is not prime 21 is undulating 21 has the prime factors: 3*7 21 in octal is 025 21 in hexadecimal is 0x15 21 in binary is 10101 (is odious) 21 nearest square numbers: -5...4 (16 [4]...25 [5]) sqrt(21) = 4.58258 ln(21) = 3.04452 log(21) = 1.32222 21 reciprocal is .04761904761904761904761904761904 21! is 5.10909e+19 21 is 6.68451 Pi years 21 is 1 score and 1 year
21
written as a Roman numeral isXXI
.
21
is semi-prime.
[wikipedia]
21
is a Fibonacci number.
[wikipedia]
21
is the sum of the first six integers.This nBAB was created in the
21
st century.Added the song title "
21
st Century Life" to Songs With Numbers In Their Titles.Update::2013.02.21
This update was made on February
21
st when Pi Day 2013 was21
days away. This nBAB was created in 2008 and the following is MBNA output for the number21
on21
February 2013.MathBabbler Number Analyst (MBNA) output: ========================================= 21 is a natural, whole, integer 21 is odd 21 proper divisors are: 1,3,7, 21 is deficient (sum of divisors is 11) 21 is unhappy 21 is a Squarefree Number 21 is a Harshad number 21 is not prime 21 has the prime factors: 3*7 (sum=10) 21 is semiprime (biprime or 2-almost prime) 3...7...answer: 10 21 is undulating 21 is a Fibonacci number 21 is a Padovan number(12+9) 21 is a lucky number 21 is triangular 21 in octal is 025 21 in hexadecimal is 0x15 21 in binary is 10101 (is odious) 21 nearest square numbers: -5...4 (16...25 [5]) sqrt(21) = 4.58258 ln(21) = 3.04452 log(21) = 1.32222 21 reciprocal is .04761904761904761904761904761904 21! is 5.10909e+19 21 is 6.68451 Pi years 21 is 1 score and 1 year 21 written as a Roman numeral is XXI 21 = 11^2 - 10^2 and 11 + 10 = 21
Creator: Gerald Thurman
[gthurman@gmail.com]
Created: 05 December 2008