| ||||
|---|---|---|---|---|
| Cardinal | two hundred twenty-two | |||
| Ordinal | 222nd (two hundred twenty-second) | |||
| Factorization | 2 × 3 × 37 | |||
| Greek numeral | ΣΚΒ´ | |||
| Roman numeral | CCXXII | |||
| Binary | 110111102 | |||
| Ternary | 220203 | |||
| Senary | 10106 | |||
| Octal | 3368 | |||
| Duodecimal | 16612 | |||
| Hexadecimal | DE16 | |||
222 (two hundred [and] twenty-two) is the natural number following 221 and preceding 223.
In mathematics
[edit]It is a decimal repdigit[1] and a strobogrammatic number (meaning that it looks the same turned upside down on a calculator display).[2] It is one of the numbers whose digit sum in decimal is the same as it is in binary.[3]
222 is a noncototient, meaning that it cannot be written in the form n − φ(n) where φ is Euler's totient function counting the number of values that are smaller than n and relatively prime to it.[4]
There are exactly 222 distinct ways of assigning a meet and join operation to a set of ten unlabelled elements in order to give them the structure of a lattice,[5] and exactly 222 different six-edge polysticks.[6]
References
[edit]- ^ Sloane, N. J. A. (ed.). "Sequence A010785 (Repdigit numbers, or numbers with repeated digits)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A018846 (Strobogrammatic numbers: numbers that are the same upside down (using calculator-style numerals))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A037308 (Numbers n such that (sum of base 2 digits of n) = (sum of base 10 digits of n))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A005278 (Noncototients: n such that x-phi(x) = n has no solution)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A006966 (Number of lattices on n unlabeled nodes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A019988 (Number of ways of embedding a connected graph with n edges in the square lattice)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction