9666988857 has 6 divisors (see below), whose sum is σ = 13963428362. Its totient is φ = 6444659232.

The previous prime is 9666988831. The next prime is 9666988873. The reversal of 9666988857 is 7588896669.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 7585713216 + 2081275641 = 87096^2 + 45621^2 .

It is not a de Polignac number, because 9666988857 - 2⁷ = 9666988729 is a prime.

It is a super-2 number, since 2×9666988857² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9666988057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 537054928 + ... + 537054945.

Almost surely, 2^9666988857 is an apocalyptic number.

It is an amenable number.

9666988857 is a deficient number, since it is larger than the sum of its proper divisors (4296439505).

9666988857 is a wasteful number, since it uses less digits than its factorization.

9666988857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1074109879 (or 1074109876 counting only the distinct ones).

The product of its digits is 313528320, while the sum is 72.

The square root of 9666988857 is about 98320.8465026619. The cubic root of 9666988857 is about 2130.2491760334.

The spelling of 9666988857 in words is "nine billion, six hundred sixty-six million, nine hundred eighty-eight thousand, eight hundred fifty-seven".