Subtracting 66667 from its reverse (76666), we obtain a palindrome (9999).
It is a happy number.
It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 76666 = 2 ⋅38333.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-66667 is a prime.
It is a magnanimous number.
It is a Duffinian number.
66667 is a lucky number.
It is a plaindrome in base 10.
266667 is an apocalyptic number.
66667 is a wasteful number, since it uses less digits than its factorization.
66667 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 572.
The square root of 66667 is about 258.1995352436. The cubic root of 66667 is about 40.5480808837.
The spelling of 66667 in words is "sixty-six thousand, six hundred sixty-seven".