1666115115666 has 16 divisors (see below), whose sum is σ = 3332245169088. Its totient is φ = 555369215600.

The previous prime is 1666115115631. The next prime is 1666115115713. The reversal of 1666115115666 is 6665115116661.

It is an unprimeable number.

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, 1270336 + ... + 2223956.

It is an arithmetic number, because the mean of its divisors is an integer number (208265323068).

Almost surely, 2^{1666115115666} is an apocalyptic number.

1666115115666 is an abundant number, since it is smaller than the sum of its proper divisors (1666130053422).

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

1666115115666 is a wasteful number, since it uses less digits than its factorization.

1666115115666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1244817.

The product of its digits is 1166400, while the sum is 51.

The spelling of 1666115115666 in words is "one trillion, six hundred sixty-six billion, one hundred fifteen million, one hundred fifteen thousand, six hundred sixty-six".