1668385666 has 8 divisors (see below), whose sum is σ = 2502841104. Its totient is φ = 834105300.

The previous prime is 1668385643. The next prime is 1668385699. The reversal of 1668385666 is 6665838661.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 16560 + ... + 60091.

It is an arithmetic number, because the mean of its divisors is an integer number (312855138).

Almost surely, 2^1668385666 is an apocalyptic number.

1668385666 is a deficient number, since it is larger than the sum of its proper divisors (834455438).

1668385666 is a wasteful number, since it uses less digits than its factorization.

1668385666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87536.

The product of its digits is 7464960, while the sum is 55.

The square root of 1668385666 is about 40845.8769767525. The cubic root of 1668385666 is about 1186.0385812519.

The spelling of 1668385666 in words is "one billion, six hundred sixty-eight million, three hundred eighty-five thousand, six hundred sixty-six".