1666666685185 has 4 divisors (see below), whose sum is σ = 2000000022228. Its totient is φ = 1333333348144.

The previous prime is 1666666685171. The next prime is 1666666685191. The reversal of 1666666685185 is 5815866666661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 564265382976 + 1102401302209 = 751176^2 + 1049953^2 .

It is a cyclic number.

It is not a de Polignac number, because 1666666685185 - 2¹⁹ = 1666666160897 is a prime.

It is a Duffinian number.

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, 166666668514 + ... + 166666668523.

It is an arithmetic number, because the mean of its divisors is an integer number (500000005557).

Almost surely, 2^{1666666685185} is an apocalyptic number.

It is an amenable number.

1666666685185 is a deficient number, since it is larger than the sum of its proper divisors (333333337043).

1666666685185 is an equidigital number, since it uses as much as digits as its factorization.

1666666685185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333333337042.

The product of its digits is 447897600, while the sum is 70.

The spelling of 1666666685185 in words is "one trillion, six hundred sixty-six billion, six hundred sixty-six million, six hundred eighty-five thousand, one hundred eighty-five".