547

547, written five hundred forty-seven, is a natural number that follows 546 and precedes 548. It is an odd three-digit integer, and in many mathematical contexts it is treated as a prime number.

Mathematically, 547 is prime; it has no divisors other than 1 and itself. It is the 101st prime number, placing it near the beginning of the larger prime sequence. Since 547 ≡ 3 mod 4, it cannot be expressed as a sum of two squares. The number is not a happy number, as repeated sum-of-squares of digits enters the non-happy cycle (for example, 5^2+4^2+7^2=90, and the sequence eventually cycles through 4, 16, 37, 58, 89, 145, 42, 20).

In numeral systems, 547 is represented as DXLVII in Roman numerals. In common positional bases, it is 1000100011 in binary, 0x223 in hexadecimal, and 1043 in octal.

Outside pure arithmetic, 547 may appear as a model number, catalog identifier, or code in various domains.