1666687185187 has 16 divisors (see below), whose sum is σ = 1748615489280. Its totient is φ = 1586393776800.

The previous prime is 1666687185167. The next prime is 1666687185217. The reversal of 1666687185187 is 7815817866661.

It is a cyclic number.

It is not a de Polignac number, because 1666687185187 - 2²⁷ = 1666552967459 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666687185167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24515512 + ... + 24583402.

It is an arithmetic number, because the mean of its divisors is an integer number (109288468080).

Almost surely, 2^{1666687185187} is an apocalyptic number.

1666687185187 is a deficient number, since it is larger than the sum of its proper divisors (81928304093).

1666687185187 is a wasteful number, since it uses less digits than its factorization.

1666687185187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79914.

The product of its digits is 162570240, while the sum is 70.

The spelling of 1666687185187 in words is "one trillion, six hundred sixty-six billion, six hundred eighty-seven million, one hundred eighty-five thousand, one hundred eighty-seven".