227 (number)

← 226 227 228 →
← 200 210 220 230 240 250 260 270 280 290 → List of numbers — Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	two hundred twenty-seven
Ordinal	227th (two hundred and twenty-seventh)
Factorization	227
Prime	yes
Roman numeral	CCXXVII
Binary	111000112
Ternary	221023
Quaternary	32034
Quinary	14025
Senary	10156
Octal	3438
Duodecimal	16B12
Hexadecimal	E316
Vigesimal	B720
Base 36	6B36

227 (two hundred [and] twenty-seven) is the natural number between 226 and 228. It is also a prime number.

In mathematics

227 is a twin prime and the start of a prime triplet (with 229 and 233).^[1] It is a safe prime, as dividing it by two and rounding down produces the Sophie Germain prime 113.^[2] It is also a regular prime,^[3] a Pillai prime,^[4] a Stern prime,^[5] and a Ramanujan prime.^[6]

The 227th harmonic number is the first to exceed six.^[7] There are 227 different connected graphs with eight edges,^[8] and 227 independent sets in a 3 × 4 grid graph.^[9]

See also

• 227 (TV series), an NBC sitcom which ran from 1985-1990.

References

1. "Sloane's A022004". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
2. "Sloane's A005385". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
3. "Sloane's A007703 : Regular primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
4. "Sloane's A063980 : Pillai primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
5. "Sloane's A042978". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
6. "Sloane's A104272 : Ramanujan primes". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
7. "Sloane's A002387 : Least k such that H(k) > n, where H(k) is the harmonic number sum_{i=1..k} 1/i". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
8. "Sloane's A002905". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
9. "Sloane's A051736". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.