Number System 

Natural Number (प्राकृतिक संख्याएँ ):  Those Number's are called Natural Numbers which are used for counting, it is denoted by 'N' , The smallest natural number is 1 'One' , there are no any highest number, 0 'Zero' is not a natural number. N={1,2,3,4,5,6,7,8,9,10,11,12...…Infinite}

Whole Number (पूर्ण संख्याएँ ): Those Number's are whole numbers which are starts from 0 'zero'    W={0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15...........Infinite}, It is denoted by 'W', there are no any highest numbers.

Integers (पूर्णांक ): Whole negative & whole positive number including 0 'zero' are called Integer numbers, it is denoted by 'I', there are no any minimum & maximum number present in this set.              I={ Infinite.............-10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10,11,..........Infinite}

Even Numbers (सम संख्याएँ ): Those Number's are Even numbers which are Fully divisible by 2, is called even numbers, it is denoted by 'E'  E={0,2,4,6,8,10,12,14,16,18,20,22,24,26,.........Infinite}

Odd Numbers (विषम संख्याएँ ): Those Number's are Odd numbers which are Not Fully divisible by 2, is called odd numbers, it is denoted by 'O'  O={1,3,5,7,9,11,13,15,17,.........Infinite}

Prime Numbers (अभाज्य संख्याएँ ): Those Natural Number's are Prime Numbers which have only two multiplication factor  'One' & 'Itself ' , it is denoted by 'P'   P= {2,3,5,7,11,13,17,19.........Infinite}

Coprime Numbers (सहअभाज्य संख्याएँ ): Those Number's are Coprime numbers which common factor is always '1'

Example: [5,11],[2,3],[17,19],[21,23].................

Composite Numbers (भाज्य संख्याएँ  या  संयुक्त संख्याएँ ): Those Number's are composite numbers which have other multiplication factors other than 'one' & 'itself '

Example: [4,6,8,9,10,12,14,15,16,18,20,21,22,24,25,26,.................]

Note: 'One' is not a Prime Number nor Composite Number

Rational Numbers (परिमेय  संख्याएँ ): p/q के रूप वाली कोई संख्या , जहाँ p एवं q सहअभाज्य पूर्णांक हों तथा q≠0,  एक परिमेय सँख्या कहलाती है 

Example: 2/3,3/4.5/9,-4/7,.......................

परिमेय संख्याओ  के दो प्रकार के दशमलव निरूपण सम्भव हैं -

(1). सांत दशमलव  --  [1/4=0.25], [1/8=0.125], [29/20=1.45]

(2). असांत दशमलव  -- [1/3=0.3333333333333...................], [11/7=1.571428571428.........]

Irrational Numbers (अपरिमेय  संख्याएँ ): वे संख्याएँ जो परिमेय नहीं होती , अपरिमेय संख्याएँ कहलाती हैं !

Example: √2=1.4142135........., √3=1.73205........., 𝝅=3.141592654........

Real Numbers (वास्तविक संख्याएँ  ): जिसमें परिमेय और अपरिमेय संख्यायें दोनों सामिल हों वास्तविक संख्याएँ कहलाती हैं