### Read and Write Roman Numeral XXI

Roman numeral symbols are written and read from left to right, from highest to lowest values. If XXI is text, it is the number 21. Find XXI in numbers and convert XXI to decimal and binary..

### Miscellaneous & Conversions For 21

 Text Twenty-One Roman Numeral: 21 XXI RGB Colour (# 015 or #000015)

 Decimal / Number 21 Binary 10101 Ternary 210 Hexadecimal (Hex) 0x15 Quaternary 111 Quinary 41 Senary (Heximal) 33 Octal 25 Duodecimal (Dozenal) 19

### Mathematics

 Prime Factors: 3 x 7 = 21 Factorial: 21! 5.10909421717E+19 Harshad Number: 21 True Triangular Number Of 21 231 Square Root: √21 4.58257569496 Cube Root (Root 3): 3√21 2.75892417638 Tesseract Root (Root 4): 4√21 2.14069514293 Quintal / nth Root. (Root 5) 5√21 1.83841628725 ¾ Root 9.80989753229 Fibonnaci # 21 10946 Recipricol 1/ 21 0.047619047619 Quarter 1/4 5.25 or 5.25/21 Half 1/2 10.50 or 10.50/21 Third 1/3 7 or 7/21

### Roman Numeral Chart. Read & Write 21

Reading and writing roman numerals isn't common knowledge. However, this roman numeral chart should help you read and write numbers in roman numerals from 1 to 1,000,000. Using an overline symbol is times 1,000. ( Example: X means to add 3 zeros to your number. So X which is 5, but written as X with the overline is 5,000.

• When a symbol appears after a larger symbol it is added: Example: VI = V + I = 5 + 1 = 6
• When a symbol appears before a larger symbol it is subtracted: Example: IX = X - I = 10 - 1 = 9
• Do not use the same symbol more than 3 times. But, IIII is sometimes used for 4
 1 I 10 x 500 D 1,001 MI 2 II 20 XX 501 DI 1,002 MII 3 III 30 XXX 530 DXXX 1,030 MXXX 4 IV 40 XL 550 DL 1,550 MDL 5 V 50 L 600 DC 1,555 MDLV 6 VI 60 LX 650 DCL 5,000 V 7 VII 70 LXX 700 DCC 10,000 X 8 VIII 80 LXXX 800 DCCC 50,000 L 9 IX 90 XC 890 DCCCXC 100,000 C 10 X 95 XCV 900 CM 500,000 D 11 XI 99 XCIX 950 CML 1,000,000 M 12 XII... 100 C 1000 M
 31 xxxi 34 xxxiv 32 xxxii 1,031 mxxxi 131 cxxxi 38 xxxviii 3,037 mmmxxxvii 35 xxxv

2% Fibonacci
38% Numbers
20% Binary