67 (number)
{{Infobox number
| number = 67
| factorization = prime
| prime = 19th
| divisor = 1, 67
}}
67 (sixty-seven) is the natural number following 66 and preceding 68. It is an odd and prime number.
In mathematics
67 is:
- the 19th prime number (the next is 71).
- a Chen prime.{{Cite web|url=https://oeis.org/A109611|title=Sloane's A109611: Chen primes|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2021-01-08}}
- an irregular prime.{{Cite web|url=https://oeis.org/A000928|title=Sloane's A000928 : Irregular primes|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-29}}
- a lucky prime.{{Cite web|url=https://oeis.org/A031157|title=Sloane's A031157 : Numbers that are both lucky and prime|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-29}}
- the sum of five consecutive primes (7 + 11 + 13 + 17 + 19).
- a Heegner number.{{Cite web|url=https://oeis.org/A003173|title=Sloane's A003173 : Heegner numbers|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-29}}
- a Pillai prime since 18! + 1 is divisible by 67, but 67 is not one more than a multiple of 18.{{Cite web|url=https://oeis.org/A063980|title=Sloane's A063980 : Pillai primes|website=The On-Line Encyclopedia of Integer Sequences|publisher=OEIS Foundation|access-date=2016-05-29}}
- palindromic in quinary (2325) and senary (1516).
- a super-prime. (19 is prime)
- an isolated prime. (65 and 69 are not prime)
- a sexy prime with 61 and 73
References
{{Reflist}}
{{Integers|zero}}