價格：免費
更新日期：2019-06-23
檔案大小：717k
目前版本：V9.01
版本需求：Android 5.0 以上版本
官方網站：http://infosoft.biz
Email：info@infosoft.biz
聯絡地址：attn: Alexander Bell 94-01 64th Road #5L REGO PARK, NY 11374 USA
INTRODUCTION
A Prime Number is a natural (a.k.a. counting) number that has exactly two distinct divisors called trivial factors, namely: number 1 and itself. Any other factors are considered non-trivial. Any natural number other than Prime is a composite number. Composite numbers are made of their non-trivial factors - they equal to the product of said factors. Number 1 is neither prime nor composite.
OVERVIEW
Prime Factorization is a mathematical task of finding not-trivial factors of any given natural number; if they don't exist then the number under the test is a Prime number.
For example, number 6 has two non-trivial factors 2 and 3, therefore 6 = 2 * 3; number 15 also has two non-trivial factors 3 and 5 (15 = 3 * 5); number 100 has 4 non-trivial factors, namely: 2, 2, 5, 5, thus 100 = 2 * 2 * 5 * 5. On the other side, the Prime numbers 2, 3 and 5 do not have any non-trivial factors: they are evenly divisible (i.e. divisible without remainder) only by the number 1 and the number itself.
Note: in this notation the asterisk "*" means arithmetic multiplication, same as "x" symbol (they can be used interchangeably, thus it could be written: 6 = 2 x 3).
Summary: Prime Numbers do not have any non-trivial factors, like 3, 5, 7 11. Any number with two or more non-trivial factors is called a Composite number, like said number 6, or number 9 (9 = 3 * 3), or 10 (10 = 2 * 5), etc.
USAGE
To find the prime factors, enter the number in the text box using on-screen keypad and click on enter button "=". Result will appear on digital displaying, showing either the list of found prime factors, or the message indicating that input number is Prime.
Calculator is capable of processing large numbers up to 18 digits. Please be aware that calculation of such big numbers may take several seconds, depends on the type of CPU (processor) used in Android cellphone or tablet.
PLATFORMS
This app can run in any Cellphone or Tablet equipped with Android 5 or higher (i.e. Android Lollipop / Marshmallow / Nougat / Oreo / Pie).
ALGORITHM
Looking "under the hood", the Calculator implements sophisticated parallel "Wheel Factorization" algorithm optimized for octal-core processor found in most Android cellphones Prime factorization of a large 18-digits Primes requires heavy "number crunching", so the computation time could be in range of seconds, depends on smartphone/tablet hardware.
Speed Test
This app implements speed benchmark - see sample screenshots taken on two different smartphones: Sony Xperia XA2 (Android Oreo 8.0) and Motorola Moto G5 Plus (Android Nougat 7.0)
REFERENCE
3 largest 14-Digit Prime numbers
99999999999973
99999999999971
99999999999959
3 largest 15-Digit Prime numbers
999999999999989
999999999999947
999999999999883
3 largest 16-Digit Prime numbers
9999999999999937
9999999999999917
9999999999999887
3 largest 17-Digit Prime numbers
99999999999999997
99999999999999977
99999999999999961
3 largest 18-Digit Prime numbers
999999999999999989
999999999999999967
999999999999999877
ABOUT
This app is brought to you by Infosoft International Inc, a NY hi-tech Company providing quality educational resources since 1998. Unique prime factorization algorithm and other major developments are credited to Dr. Alexander Bell.
Keywords: #Prime #Numbers #Calculator, #Prime #Wheel #Factorization #Algorithm, #Number #Theory, #School #Math, #Online #Education, #eLearning, #Tutoring, #Homeschooling, #Mobile #Cellphone #Tablet
