666888666 has 32 divisors (see below), whose sum is σ = 1371410880. Its totient is φ = 216038016.

The previous prime is 666888637. The next prime is 666888667.

666888666 is nontrivially palindromic in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (666888667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 356265 + ... + 358131.

It is an arithmetic number, because the mean of its divisors is an integer number (42856590).

Almost surely, 2^666888666 is an apocalyptic number.

666888666 is an abundant number, since it is smaller than the sum of its proper divisors (704522214).

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

666888666 is a wasteful number, since it uses less digits than its factorization.

666888666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3518.

The product of its digits is 23887872, while the sum is 60.

The square root of 666888666 is about 25824.1876154895. The cubic root of 666888666 is about 873.6774211154.

The spelling of 666888666 in words is "six hundred sixty-six million, eight hundred eighty-eight thousand, six hundred sixty-six".