9666838999 has 2 divisors, whose sum is σ = 9666839000. Its totient is φ = 9666838998.

The previous prime is 9666838997. The next prime is 9666839009. The reversal of 9666838999 is 9998386669.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9666838999 - 2¹ = 9666838997 is a prime.

Together with 9666838997, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9666838997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4833419499 + 4833419500.

It is an arithmetic number, because the mean of its divisors is an integer number (4833419500).

Almost surely, 2^9666838999 is an apocalyptic number.

9666838999 is a deficient number, since it is larger than the sum of its proper divisors (1).

9666838999 is an equidigital number, since it uses as much as digits as its factorization.

9666838999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 272097792, while the sum is 73.

The square root of 9666838999 is about 98320.0844131045. The cubic root of 9666838999 is about 2130.2381682441.

The spelling of 9666838999 in words is "nine billion, six hundred sixty-six million, eight hundred thirty-eight thousand, nine hundred ninety-nine".