1668551853666 has 16 divisors (see below), whose sum is σ = 3512740744800. Its totient is φ = 526911111648.

The previous prime is 1668551853659. The next prime is 1668551853667. The reversal of 1668551853666 is 6663581558661.

It is a junction number, because it is equal to n+sod(n) for n = 1668551853597 and 1668551853606.

It is not an unprimeable number, because it can be changed into a prime (1668551853667) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 7318209771 + ... + 7318209998.

It is an arithmetic number, because the mean of its divisors is an integer number (219546296550).

Almost surely, 2^{1668551853666} is an apocalyptic number.

1668551853666 is an abundant number, since it is smaller than the sum of its proper divisors (1844188891134).

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

1668551853666 is a wasteful number, since it uses less digits than its factorization.

1668551853666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14636419793.

The product of its digits is 186624000, while the sum is 66.

The spelling of 1668551853666 in words is "one trillion, six hundred sixty-eight billion, five hundred fifty-one million, eight hundred fifty-three thousand, six hundred sixty-six".