242 (number)
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Cardinal | two hundred forty-two | |||
Ordinal | 242nd (two hundred forty-second) | |||
Factorization | 2 × 112 | |||
Greek numeral | ΣΜΒ´ | |||
Roman numeral | CCXLII | |||
Binary | 111100102 | |||
Ternary | 222223 | |||
Senary | 10426 | |||
Octal | 3628 | |||
Duodecimal | 18212 | |||
Hexadecimal | F216 |
242 (two hundred [and] forty-two) is the natural number following 241 and preceding 243.
242 is the smallest integer to start a run of four consecutive integers with the same number of divisors.[1][2]
242 is a nontotient since there is no integer with 242 coprimes below it.
242 is a palindrome.
242 is the number of parallelogram polyominoes with 8 cells.[3]
242 is the difference between 355 and 113, two numbers used in an approximation of pi,
(This fraction is slightly larger than , by a factor of around )
242 is the sum of elements in a 5-orthoplex: 32 polychora, 80 cells, 80 faces, 40 edges, and 10 vertices.
References
[edit]- ^ R. K. Guy Unsolved Problems in Number Theory, section B18.
- ^ D. Wells, The Penguin Dictionary of Curious and Interesting Numbers, Penguin Books, NY, 1986: 147, 176.
- ^ Sloane, N. J. A. (ed.). "Sequence A006958 (Number of parallelogram polyominoes with n cells (also called staircase polyominoes, although that term is overused))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.