1666989732893 has 2 divisors, whose sum is σ = 1666989732894. Its totient is φ = 1666989732892.

The previous prime is 1666989732869. The next prime is 1666989732899. The reversal of 1666989732893 is 3982379896661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1319128052089 + 347861680804 = 1148533^2 + 589798^2 .

It is a cyclic number.

It is not a de Polignac number, because 1666989732893 - 2¹⁸ = 1666989470749 is a prime.

It is a super-2 number, since 2×1666989732893² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666989732899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833494866446 + 833494866447.

It is an arithmetic number, because the mean of its divisors is an integer number (833494866447).

Almost surely, 2^{1666989732893} is an apocalyptic number.

It is an amenable number.

1666989732893 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666989732893 is an equidigital number, since it uses as much as digits as its factorization.

1666989732893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1269789696, while the sum is 77.

The spelling of 1666989732893 in words is "one trillion, six hundred sixty-six billion, nine hundred eighty-nine million, seven hundred thirty-two thousand, eight hundred ninety-three".