9660000991 has 2 divisors, whose sum is σ = 9660000992. Its totient is φ = 9660000990.

The previous prime is 9660000953. The next prime is 9660001037. The reversal of 9660000991 is 1990000669.

It is a weak prime.

It is an emirp because it is prime and its reverse (1990000669) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9660000991 - 2⁷ = 9660000863 is a prime.

It is a super-2 number, since 2×9660000991² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9660000901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4830000495 + 4830000496.

It is an arithmetic number, because the mean of its divisors is an integer number (4830000496).

Almost surely, 2^9660000991 is an apocalyptic number.

9660000991 is a deficient number, since it is larger than the sum of its proper divisors (1).

9660000991 is an equidigital number, since it uses as much as digits as its factorization.

9660000991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26244, while the sum is 40.

The square root of 9660000991 is about 98285.3040438905. The cubic root of 9660000991 is about 2129.7357626617.

The spelling of 9660000991 in words is "nine billion, six hundred sixty million, nine hundred ninety-one", and thus it is an aban number.