666404668 has 12 divisors (see below), whose sum is σ = 1216913040. Its totient is φ = 318715232.

The previous prime is 666404653. The next prime is 666404723. The reversal of 666404668 is 866404666.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3621673 + ... + 3621856.

It is an arithmetic number, because the mean of its divisors is an integer number (101409420).

Almost surely, 2^666404668 is an apocalyptic number.

It is an amenable number.

666404668 is a deficient number, since it is larger than the sum of its proper divisors (550508372).

666404668 is a wasteful number, since it uses less digits than its factorization.

666404668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7243556 (or 7243554 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 46.

The square root of 666404668 is about 25814.8148937776. The cubic root of 666404668 is about 873.4660112832.

The spelling of 666404668 in words is "six hundred sixty-six million, four hundred four thousand, six hundred sixty-eight".