9966321647 has 2 divisors, whose sum is σ = 9966321648. Its totient is φ = 9966321646.

The previous prime is 9966321641. The next prime is 9966321671. The reversal of 9966321647 is 7461236699.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 9966321647 - 2²⁶ = 9899212783 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9966321641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4983160823 + 4983160824.

It is an arithmetic number, because the mean of its divisors is an integer number (4983160824).

Almost surely, 2^9966321647 is an apocalyptic number.

9966321647 is a deficient number, since it is larger than the sum of its proper divisors (1).

9966321647 is an equidigital number, since it uses as much as digits as its factorization.

9966321647 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2939328, while the sum is 53.

The square root of 9966321647 is about 99831.4662168196. The cubic root of 9966321647 is about 2152.0133760650.

The spelling of 9966321647 in words is "nine billion, nine hundred sixty-six million, three hundred twenty-one thousand, six hundred forty-seven".