666867 has 4 divisors (see below), whose sum is σ = 889160. Its totient is φ = 444576.

The previous prime is 666857. The next prime is 666871. The reversal of 666867 is 768666.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 666867 - 2¹⁰ = 665843 is a prime.

It is a D-number.

It is a Duffinian number.

666867 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (666857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111142 + ... + 111147.

It is an arithmetic number, because the mean of its divisors is an integer number (222290).

2⁶⁶⁶⁸⁶⁷ is an apocalyptic number.

666867 is a deficient number, since it is larger than the sum of its proper divisors (222293).

666867 is a wasteful number, since it uses less digits than its factorization.

666867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222292.

The product of its digits is 72576, while the sum is 39.

The square root of 666867 is about 816.6192503242. The cubic root of 666867 is about 87.3667959616.

The spelling of 666867 in words is "six hundred sixty-six thousand, eight hundred sixty-seven".