9897385991 has 2 divisors, whose sum is σ = 9897385992. Its totient is φ = 9897385990.

The previous prime is 9897385987. The next prime is 9897385999. The reversal of 9897385991 is 1995837989.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (1995837989) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9897385991 - 2² = 9897385987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9897385999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4948692995 + 4948692996.

It is an arithmetic number, because the mean of its divisors is an integer number (4948692996).

Almost surely, 2^9897385991 is an apocalyptic number.

9897385991 is a deficient number, since it is larger than the sum of its proper divisors (1).

9897385991 is an equidigital number, since it uses as much as digits as its factorization.

9897385991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 44089920, while the sum is 68.

The square root of 9897385991 is about 99485.6069539710. The cubic root of 9897385991 is about 2147.0401666467.

The spelling of 9897385991 in words is "nine billion, eight hundred ninety-seven million, three hundred eighty-five thousand, nine hundred ninety-one".