1666106006693 has 2 divisors, whose sum is σ = 1666106006694. Its totient is φ = 1666106006692.

The previous prime is 1666106006671. The next prime is 1666106006759. The reversal of 1666106006693 is 3966006016661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1276283094529 + 389822912164 = 1129727^2 + 624358^2 .

It is a cyclic number.

It is not a de Polignac number, because 1666106006693 - 2²⁴ = 1666089229477 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666106006293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833053003346 + 833053003347.

It is an arithmetic number, because the mean of its divisors is an integer number (833053003347).

Almost surely, 2^{1666106006693} is an apocalyptic number.

It is an amenable number.

1666106006693 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666106006693 is an equidigital number, since it uses as much as digits as its factorization.

1666106006693 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1259712, while the sum is 50.

The spelling of 1666106006693 in words is "one trillion, six hundred sixty-six billion, one hundred six million, six thousand, six hundred ninety-three".