16666668517 has 2 divisors, whose sum is σ = 16666668518. Its totient is φ = 16666668516.

The previous prime is 16666668509. The next prime is 16666668523. The reversal of 16666668517 is 71586666661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12568876321 + 4097792196 = 112111^2 + 64014^2 .

It is a cyclic number.

It is not a de Polignac number, because 16666668517 - 2³ = 16666668509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16666668017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8333334258 + 8333334259.

It is an arithmetic number, because the mean of its divisors is an integer number (8333334259).

Almost surely, 2^16666668517 is an apocalyptic number.

It is an amenable number.

16666668517 is a deficient number, since it is larger than the sum of its proper divisors (1).

16666668517 is an equidigital number, since it uses as much as digits as its factorization.

16666668517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13063680, while the sum is 58.

The spelling of 16666668517 in words is "sixteen billion, six hundred sixty-six million, six hundred sixty-eight thousand, five hundred seventeen".