547 is a prime number.
547 is a centered hexagonal number (or hex number) and a centered heptagonal number.
The number of primes between 6! and 7! is itself prime. 547 is the smallest odd prime to enumerate the primes between n! and (n + 1)! for any n.
547 is the smallest number that cannot be written using 11 copies of 11 and the operations +, -, x, /.
547 is 202021 in base 3 and 20203 in base 4. It is 4142 in base 4.
Source: Prime Curios!