663664666 has 32 divisors (see below), whose sum is σ = 1232668800. Its totient is φ = 261467136.

The previous prime is 663664657. The next prime is 663664667. The reversal of 663664666 is 666466366.

663664666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (663664667) 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, 22191 + ... + 42658.

It is an arithmetic number, because the mean of its divisors is an integer number (38520900).

Almost surely, 2^663664666 is an apocalyptic number.

663664666 is a deficient number, since it is larger than the sum of its proper divisors (569004134).

663664666 is a wasteful number, since it uses less digits than its factorization.

663664666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64918.

The product of its digits is 3359232, while the sum is 49.

The square root of 663664666 is about 25761.6898902227. The cubic root of 663664666 is about 872.2672470504.

The spelling of 663664666 in words is "six hundred sixty-three million, six hundred sixty-four thousand, six hundred sixty-six".