666108 has 18 divisors (see below), whose sum is σ = 1683864. Its totient is φ = 222024.

The previous prime is 666091. The next prime is 666109. The reversal of 666108 is 801666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666109) by changing a digit.

666108 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 5 ways as a sum of consecutive naturals, for example, 9216 + ... + 9287.

It is an arithmetic number, because the mean of its divisors is an integer number (93548).

2⁶⁶⁶¹⁰⁸ is an apocalyptic number.

It is an amenable number.

666108 is an abundant number, since it is smaller than the sum of its proper divisors (1017756).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

666108 is a wasteful number, since it uses less digits than its factorization.

666108 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18513 (or 18508 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 666108 is about 816.1543971578. The cubic root of 666108 is about 87.3336376398. Note that the first 3 decimals are identical.

The spelling of 666108 in words is "six hundred sixty-six thousand, one hundred eight".