9666808981 has 2 divisors, whose sum is σ = 9666808982. Its totient is φ = 9666808980.

The previous prime is 9666808919. The next prime is 9666809011. The reversal of 9666808981 is 1898086669.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7185274756 + 2481534225 = 84766^2 + 49815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9666808981 is a prime.

It is a super-3 number, since 3×9666808981³ (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9666808681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4833404490 + 4833404491.

It is an arithmetic number, because the mean of its divisors is an integer number (4833404491).

Almost surely, 2^9666808981 is an apocalyptic number.

It is an amenable number.

9666808981 is a deficient number, since it is larger than the sum of its proper divisors (1).

9666808981 is an equidigital number, since it uses as much as digits as its factorization.

9666808981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8957952, while the sum is 61.

The square root of 9666808981 is about 98319.9317585198. The cubic root of 9666808981 is about 2130.2359632642.

The spelling of 9666808981 in words is "nine billion, six hundred sixty-six million, eight hundred eight thousand, nine hundred eighty-one".