1666145566 has 16 divisors (see below), whose sum is σ = 2510909280. Its totient is φ = 829185280.

The previous prime is 1666145543. The next prime is 1666145573. The reversal of 1666145566 is 6655416661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 441126 + ... + 444886.

It is an arithmetic number, because the mean of its divisors is an integer number (156931830).

Almost surely, 2^1666145566 is an apocalyptic number.

1666145566 is a deficient number, since it is larger than the sum of its proper divisors (844763714).

1666145566 is a wasteful number, since it uses less digits than its factorization.

1666145566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4739.

The product of its digits is 777600, while the sum is 46.

The square root of 1666145566 is about 40818.4463937568. The cubic root of 1666145566 is about 1185.5075219848.

The spelling of 1666145566 in words is "one billion, six hundred sixty-six million, one hundred forty-five thousand, five hundred sixty-six".