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Tag Archives: Reversals
Reversals | Products : a * bcd = d * cba
(1) Consider a 4-digit integer abcd and its reversal dcba and the products: a * bcd = d * cba For example, 2 * 819 = … Continue reading
Multiples of 7 and their reversals — Part 1
Multiples of 7 under 1000: 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105, 112, 119, 126, 133, 140, 147, 154, 161, 168, 175, 182, 189, 196, 203, 210, 217, 224, 231, 238, 245, … Continue reading
Temperatures – Numbers and their reverses
16 Celsius is approximately 61 Fahrenheit and 28 Celsius ~ 82 Fahrenheit. Any others?
Num3er 2178
2178 = 2 * 3^2 * 11^2 2178 has a representation as a sum of 2 squares: 2178 = 33^2 + 33^2 2178 reverses itself: 2178 * 4 = … Continue reading
Posted in Math Beauty, Number Puzzles
Tagged Beautiful Number, Digits Reversed, Reversals
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Conjecture | Products of Integers & their Reversals: 1089
1089 = 33^2 is a perfect square. 9801 = 99^2 is a perfect square. 1089 * 9801 = 10673289 = 3^6 * 11^4 = 3267^2 is a perfect square. 144 = 12^2 441 = 21^2 144 * 441 = 63504 … Continue reading
When Num3er multiplied by its reversal is a perfect square
(1) 13 * 31 = 403, 169 = 13^2 & 961 = 31^2 169 * 961 = 162409 = 403^2 Inserting 0s, 10609 * 90601 = 961186009 = 31003^2 1006009 * 9006001 = 9060118060009 = 3010003^2 … Continue reading
Dates & Reversals on the Same Day of the Week For April
Older post: Dates & Reversals on the Same Day of the Week For Jan., Feb. & March For example Today’s date is : Sunday, March 11, 2012 So I write: 11/03/2012 … Sun The reversal of 11/03/2012 … Continue reading
Dates & Reversals on the Same Day of the Week For Jan., Feb. & March [PART ONE]
I used the “dd-mm-yyyy” format and this search engine:Day of Week Calculator Today’s date is: Sunday, March 04, 2012 So I write: 04/03/2012 … Sun The reversal of 04/03/2012 is 21/02/3040 which will occur on a Friday. They don’t share … Continue reading
4-digit Num3ers & Reversals
8712 is an integral multiple of its reversal, 2178, as 8712 = 4 * 2178 Question: Find another 4-digit number which is a non-trivial integral multiple of its reversal.
Interesting Num3ers & their reversals
91 & 19 19 is a prime number 91 = 7 * 13 91^2 = 8281 (a square formed by concatenation of 2 consecutive numbers: 8281 = 82 || 81 8 + 2 + 81 = 91 … Continue reading
