66667 has 4 divisors (see below), whose sum is σ = 67240. Its totient is φ = 66096.

The previous prime is 66653. The next prime is 66683. The reversal of 66667 is 76666.

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 2^k-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.

It is not an unprimeable number, because it can be changed into a prime (66617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42 + ... + 367.

It is an arithmetic number, because the mean of its divisors is an integer number (16810).

2⁶⁶⁶⁶⁷ is an apocalyptic number.

66667 is a deficient number, since it is larger than the sum of its proper divisors (573).

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 product of its digits is 9072, while the sum is 31.

The square root of 66667 is about 258.1995352436. The cubic root of 66667 is about 40.5480808837.

Subtracting 66667 from its reverse (76666), we obtain a palindrome (9999).

The spelling of 66667 in words is "sixty-six thousand, six hundred sixty-seven".