1666666834997 has 2 divisors, whose sum is σ = 1666666834998. Its totient is φ = 1666666834996.

The previous prime is 1666666834949. The next prime is 1666666835023. The reversal of 1666666834997 is 7994386666661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1645539921796 + 21126913201 = 1282786^2 + 145351^2 .

It is an emirp because it is prime and its reverse (7994386666661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1666666834997 - 2⁶ = 1666666834933 is a prime.

It is a super-3 number, since 3×1666666834997³ (a number of 38 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666666836997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833333417498 + 833333417499.

It is an arithmetic number, because the mean of its divisors is an integer number (833333417499).

Almost surely, 2^{1666666834997} is an apocalyptic number.

It is an amenable number.

1666666834997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666666834997 is an equidigital number, since it uses as much as digits as its factorization.

1666666834997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2539579392, while the sum is 77.

The spelling of 1666666834997 in words is "one trillion, six hundred sixty-six billion, six hundred sixty-six million, eight hundred thirty-four thousand, nine hundred ninety-seven".