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# 15

Number 15 (fifteen) is an odd two-digits composite number and natural number following 14 and preceding 16.

## Properties of the number 15

 Nominal 15 Cardinal fifteen Ordinal 15th Number of digits 2 Sum of digits 6 Product of digits 5 Number parity Odd
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## Prime Factorization of 15

 Prime factorization 3 x 5 Prime factors 3, 5 Number of distinct prime factors ω(n) 2 Total number of prime factors Ω(n) 2 Sum of prime factors 8 Product of prime factors 15
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## Divisors of 15

 List of proper divisors 1, 3, 5 List of all dividers 1, 3, 5, 15 Number of divisors d(n) 4 Sum of all divisors σ(n) 24 Aliquot sum 9 15 is a deficient number , since it is larger than the sum of its proper divisors (9). Its deficiency is 6.
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## Prime numbers

 Is 15 a prime number? No Is 15 a semiprime number? Yes Is 15 a Chen prime number? No Is 15 a Mersenne prime number? No
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## Sequences

 Is 15 a Catalan number? No Is 15 a Fibonacci number? No Is 15 a Idoneal number? Yes: I12
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## Number theory

Number theory is a branch of pure mathematics devoted primarily to the study of the integers and integer-valued functions.
 15 is not a Happy number 15 is a Humble number 15 is not a Münchhausen number 15 is not a Perfect number 15 is not a Perfect square 15 is not a Palindrome
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## Numeric Bases of 15

In mathematics, a base or radix of a numeral system is the number of unique digits, including zero, used to represent numbers in that system.
BaseSystemValue
2Binary11112
3Ternary1203
4Quaternary334
5Quinary305
6Senary236
7Septenary217
8Octal178
9Nonary169
10Decimal15
12Duodecimal1312
20Vigesimalf20
36Base36f36
60SexagesimalF60
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## Mathematical operations

Mathematical operations are actions that are performed on numbers or mathematical expressions to find a numerical result.
 Square of 15 (n2) 225 Cube of 15 (n3) 3375 Square root of 15 3.87298 Natural Logarithm (ln) of 15 2.70805 Decimal Logarithm (log) of 15 1.17609
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## Trigonometry

Trigonometry is the study of the relationship between the angles and sides of a triangle.
 Sine of 15 0.650288 Cosecant of 15 1.53778 Cosine of 15 -0.759688 Secant of 15 -1.31633 Tangent of 15 -0.855993 Cotangent of 15 -1.16823
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## Number parity

Parity is the property of an integer of whether it is even or odd.

No

### Is 15 an Odd Number?

Yes, the number 15 is an odd number.
Total number of all odd numbers from 1 to 15 is 8
Sum of all the odd numbers from 1 to 15 are 64
The sum of all odd numbers is a perfect square: 64 = 8
An odd number is any integer (a whole number) that cannot be divided by 2 evenly. Odd numbers are the opposite of even numbers.
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## Ban number

In recreational mathematics, a ban number is a number that does not contain a particular letter when spelled out in English; in other words, the letter is "banned".
 The spelling of 15 in words is "fifteen", meaning that: 15 is an aban number (a number without the letter a) 15 is not an eban number (as it contains the letter e) 15 is not an iban number (as it contains the letter i) 15 is an oban number (a number without the letter o) 15 is not a tban number (as it contains the letter t) 15 is an uban number (a number without the letter u)
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## Numeral systems

How to write 15 in other number systems?
 Bengali numerals ১৫ Eastern Arabic numerals ١٥ Hieroglyphs numeralsused in Ancient Egypt 𓎆𓏾 Khmer numerals ១៥ Japanese numerals 十五 Roman numerals XV Thai numerals ๑๕
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## Translation

How do you say 15 in 38 different languages?
 Arabic خمسة عشر Croatian petnaest Czech patnáct Danish femten Dutch vijftien Estonian wuiatɔ̃ Faroese fímtan Filipino labíng-limá Finnish viisitoista French quinze Greek δεκα­πέντε German fünfzehn Hebrew חמש עשרה Hindi पन्द्रह Hungarian tizen­öt Icelandic fimmtán Indonesian lima belas Italian quindici Japanese 十五 Korean 십오 Latvian piecpadsmit Lithuanian penkiolika Norwegian femten Persian پانزده Polish piętnaście Portuguese quinze Romanian cincisprezece Russian пятнадцать Serbian петнаест Slovak pätnásť Slovene petnajst Spanish quince Swahili kumi na tano Swedish femton Thai สิบ​ห้า Turkish on beş Ukrainian пʼятнадцять Vietnamese mười lăm
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## Miscellaneous

 Number 15 reversed 51 ASCII Code 15  Unicode Character U+000F  Unix Timestamp Thu, 01 Jan 1970 00:00:15 +0000
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