666168 has 32 divisors (see below), whose sum is σ = 1708560. Its totient is φ = 216320.

The previous prime is 666167. The next prime is 666173. The reversal of 666168 is 861666.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666167) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 646 + ... + 1322.

2⁶⁶⁶¹⁶⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (854280).

666168 is an abundant number, since it is smaller than the sum of its proper divisors (1042392).

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

666168 is a wasteful number, since it uses less digits than its factorization.

666168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727 (or 723 counting only the distinct ones).

The product of its digits is 10368, while the sum is 33.

The square root of 666168 is about 816.1911540810. The cubic root of 666168 is about 87.3362597677.

The spelling of 666168 in words is "six hundred sixty-six thousand, one hundred sixty-eight".