9909897961 has 2 divisors, whose sum is σ = 9909897962. Its totient is φ = 9909897960.

The previous prime is 9909897947. The next prime is 9909897973. The reversal of 9909897961 is 1697989099.

9909897961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6061556736 + 3848341225 = 77856^2 + 62035^2 .

It is a cyclic number.

It is not a de Polignac number, because 9909897961 - 2²⁹ = 9373027049 is a prime.

It is not a weakly prime, because it can be changed into another prime (9909817961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4954948980 + 4954948981.

It is an arithmetic number, because the mean of its divisors is an integer number (4954948981).

Almost surely, 2^9909897961 is an apocalyptic number.

It is an amenable number.

9909897961 is a deficient number, since it is larger than the sum of its proper divisors (1).

9909897961 is an equidigital number, since it uses as much as digits as its factorization.

9909897961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19840464, while the sum is 67.

The square root of 9909897961 is about 99548.4704101474. The cubic root of 9909897961 is about 2147.9445263108.

The spelling of 9909897961 in words is "nine billion, nine hundred nine million, eight hundred ninety-seven thousand, nine hundred sixty-one".