9171720889 has 2 divisors, whose sum is σ = 9171720890. Its totient is φ = 9171720888.

The previous prime is 9171720851. The next prime is 9171721057. The reversal of 9171720889 is 9880271719.

9171720889 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4921724025 + 4249996864 = 70155^2 + 65192^2 .

It is a cyclic number.

It is not a de Polignac number, because 9171720889 - 2¹⁵ = 9171688121 is a prime.

It is not a weakly prime, because it can be changed into another prime (9171720589) 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, 4585860444 + 4585860445.

It is an arithmetic number, because the mean of its divisors is an integer number (4585860445).

Almost surely, 2^9171720889 is an apocalyptic number.

It is an amenable number.

9171720889 is a deficient number, since it is larger than the sum of its proper divisors (1).

9171720889 is an equidigital number, since it uses as much as digits as its factorization.

9171720889 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 508032, while the sum is 52.

The square root of 9171720889 is about 95769.1019536051. The cubic root of 9171720889 is about 2093.2299659196.

The spelling of 9171720889 in words is "nine billion, one hundred seventy-one million, seven hundred twenty thousand, eight hundred eighty-nine".