511 (number)

← 510 511 512 ⊟
List of numbers Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	five hundred eleven
Ordinal	511th (five hundred eleventh)
Factorization	7 × 73
Greek numeral	ΦΙΑ´
Roman numeral	DXI
Binary	1111111112
Ternary	2002213
Senary	22116
Octal	7778
Duodecimal	36712
Hexadecimal	1FF16

511 is the natural number following 510 and preceding 512.

It is a Mersenne number, being one less than a power of 2: $511=2^{9}-1$. As a result, 511 is a palindromic number and a repdigit in bases 2 (111111111₂). It is also palindromic and a repdigit in base 8 (777₈).

It is a generalized heptagonal number (sequence A085787 in the OEIS), since $511={\frac {1}{2}}(5n^{2}-3n)$ when $n=-14$.

It is a Harshad number in bases 3, 5, 7, 10, 13 and 15.

Special use in computers

The octal representation of 511 (777₈) is commonly used by Unix commands to specify a custom record separator in order to "slurp" input as a whole, rather than line-by-line (i.e. separated at newline characters).