54321 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.
It is a sphenic number, since it is the product of 3 distinct primes.
It is an alternating number because its digits alternate between odd and even.
It is a Curzon number.
It is a straight-line number, since its digits are in arithmetic progression.
It is a plaindrome in base 15.
It is a nialpdrome in base 10 and base 16.
It is a zygodrome in base 15.
It is a self number, because there is not a number n which added to its sum of digits gives 54321.
254321 is an apocalyptic number.
It is an amenable number.
54321 is a wasteful number, since it uses less digits than its factorization.
54321 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 975.
The square root of 54321 is about 233.0686594118. The cubic root of 54321 is about 37.8723788882.
Adding to 54321 its reverse (12345), we get a palindrome (66666).
The spelling of 54321 in words is "fifty-four thousand, three hundred twenty-one".