666858668 has 48 divisors (see below), whose sum is σ = 1359880704. Its totient is φ = 280247040.

The previous prime is 666858641. The next prime is 666858691. The reversal of 666858668 is 866858666.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 307508 + ... + 309668.

It is an arithmetic number, because the mean of its divisors is an integer number (28330848).

Almost surely, 2^666858668 is an apocalyptic number.

It is an amenable number.

666858668 is an abundant number, since it is smaller than the sum of its proper divisors (693022036).

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

666858668 is a wasteful number, since it uses less digits than its factorization.

666858668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2382 (or 2380 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 59.

The square root of 666858668 is about 25823.6067968826. The cubic root of 666858668 is about 873.6643209936.

The spelling of 666858668 in words is "six hundred sixty-six million, eight hundred fifty-eight thousand, six hundred sixty-eight".