49 |
is the smallest number with the property that it and its bordering numbers are squareful: 48 = 4^{2} x 3, 49 = 7^{2 }x 1, 50 = 5^{2} x 2
is the smallest number which is the concatenation of two prime squares (2^{2} and 3^{2}) creating another prime square.
is a 'lucky numbers'. Stanislaw Ulam, a polish mathematician, devised a sequence of numbers called lucky numbers which are generated by a simple algorithm called 'sieve' similar to the 'Sieve of Eratosthenes'. The lucky numbers are: 1, 3, 7, 9, 13, 15, 21, 25, 31, 33, 37, 43, **49**, 51, 63, 67, 69, 73, 75, 79, 87, 93, 99, 105, 111, 115, 127, 129, 133, 135, 141, 151, 159, 163, etc.
Its cube ends in the same digits: 49^{3} = 117,6**49**
49 = 4 x 9 + 4 + 9 This also works for 19, 29, 39, 59, 69, 79, 89 and 99, for instance: 79 = 7 x 9 + 7 + 9
= 1 + 3 + 5 + 7 + 9 + 11 + 13 (sum of the first seven odd numbers) = 13 + 17 + 19 (sum of consecutive primes) = 7^{2} = 25^{2} - 24^{2} = 25 + 24 = (11 - **4**)^{(11 - 9)} = 3^{2} + 5^{2} + 3 x 5 = 3^{2} + 10 x 2^{2} = 5^{2} + 6 x 2^{2}
49 = 4 + 9 1/49 = 0,0**2**0**4**0**8****16****32****64**...
__49__ = __4__**9** = __4__ 98 **9**8 8
2^{3n+3 }- 7n - 8 (this algebraic expression is divisible by 49)
XLIX or IL? Rules regarding Roman numerals often state that L cannot be preceded by I or V, only by X. Thus, one should represent the number 'forty-nine' as XLIX, not as the 'shortcut' IL.
*Lasca* is an unusual checkers game played on a 7x7 board having 49 squares.
The "Nagari" or "Devanagari" (also called 'writing of the gods') is a writing system employed for the traditional Sanskrit language and has 49 elementary signs. |