1668106666 has 8 divisors (see below), whose sum is σ = 2502417060. Its totient is φ = 833967648.

The previous prime is 1668106639. The next prime is 1668106669. The reversal of 1668106666 is 6666018661.

It can be written as a sum of positive squares in 2 ways, for example, as 1662274441 + 5832225 = 40771^2 + 2415^2 .

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

It is not an unprimeable number, because it can be changed into a prime (1668106669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14851 + ... + 59638.

Almost surely, 2^1668106666 is an apocalyptic number.

1668106666 is a deficient number, since it is larger than the sum of its proper divisors (834310394).

1668106666 is a wasteful number, since it uses less digits than its factorization.

1668106666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85688.

The product of its (nonzero) digits is 373248, while the sum is 46.

The square root of 1668106666 is about 40842.4615565712. The cubic root of 1668106666 is about 1185.9724648021.

The spelling of 1668106666 in words is "one billion, six hundred sixty-eight million, one hundred six thousand, six hundred sixty-six".