17

17
Basic Information
Cardinal Number	seventeen
Ordinal Number	seventeenth
Roman Numeral	XVII
Greek Numeral	ΙΖ´
Factorization	17
Standard Form	1.7 × 101
Different Representations
Binary Form	100012
Ternary Form	1223
Quaternary Form	1014
Quinary Form	325
Senary Form	256
Septenary Form	237
Octal Form	218
Nonary Form	189
Undecimal Form	1611
Duodecimal Form	1512
Tridecimal Form	1413
Quattuordecimal Form	1314
Quindecimal Form	1215
Hexadecimal Form	1116
Septendecimal Form	1017
Octodecimal Form	H18
Novemdecimal Form	H19
Vigesimal Form	H20
Unvigesimal Form	H21
Duovigesimal Form	H22
Trevigesimal Form	H23
Quattuorvigesimal Form	H24
Quinvigesimal Form	H25
Hexavigesimal Form	H26
Septenvigesimal Form	H27
Octovigesimal Form	H28
Novemvigesimal Form	H29
Trigesimal Form	H30
Untrigesimal Form	H31
Duotrigesimal Form	H32
Tretrigesimal Form	H33
Quattuortrigesimal Form	H34
Quintrigesimal Form	H35
Hexatrigesimal Form	H36
Previous	13
Current	17
Next	19

17 is a prime number from 1-100. 17 has two factors, 1 and 17. It is the number with the most syllables within the range of 13-19, due to containing "seven", which has 2 syllables on its own. It is the seventh prime number and the seventh prime number from 1-100. The primorial of 17 is 510,510.

Proofs

• — 17 is divisible by 1.

• — 17 is not divisible by 2-16.

• — 17 is divisible by 17.

• Therefore, 17 has 2 factors

As an Exponent of Mersenne Number

2¹⁷ - 1, which is the number 131,071, is a prime number. It is the 6th Mersenne prime.

​Relationship with other odd numbers

The numbers before

• 11 is the second previous prime number.
  • The difference between 17 and 11 is 6. Therefore, they are sexy primes.
• 13 is the previous prime number.
  • The difference between 17 and 13 is 4. Therefore, they are cousin primes.
• 15 is the previous odd number. It is not prime, as it is divisible by 3 and 5.

The numbers after

• The next odd number, 19, is a prime number.
  • There are no odd numbers between 17 and 19. As a result, they are twin primes.
• 21, the odd number following 19, is the third odd composite number. It is divisible by 3 and 7.
• 23, the odd number following 21, is a prime number.
  • The difference between 23 and 17 is 6. Therefore, they are sexy primes.

Trivia

• 17 is in the only sexy prime quintuplet (5, 11, 17, 23, 29) since all multiples of 5 (except itself) are composite numbers.
• 17 is described by the MIT as the "least random number," since, in a study where respondents were asked to choose a random number between 1 and 20, 17 was the most common answer.
• 17 is a Leyland prime: 17 = 2³ + 3² = 8 + 9
• 17 is the total number of syllables in a haiku (5 + 7 + 5 = 17).
• Heptadecaphobia is the fear of the number 17. The date Friday the 17th is considered unlucky in Italy due to superstition.
  • The Romans found the number 17 disturbing since its expression in Roman numerals is XVII, which is an anagram of the word vixi, which means "I have lived," implying "I am dead."

Prime Numbers 1-1,000