9107989721 has 2 divisors, whose sum is σ = 9107989722. Its totient is φ = 9107989720.

The previous prime is 9107989699. The next prime is 9107989729. The reversal of 9107989721 is 1279897019.

9107989721 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., 4650558025 + 4457431696 = 68195^2 + 66764^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9107989721 is a prime.

It is a super-4 number, since 4×9107989721⁴ (a number of 41 digits) contains 4444 as substring.

It is not a weakly prime, because it can be changed into another prime (9107989729) 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, 4553994860 + 4553994861.

It is an arithmetic number, because the mean of its divisors is an integer number (4553994861).

Almost surely, 2^9107989721 is an apocalyptic number.

It is an amenable number.

9107989721 is a deficient number, since it is larger than the sum of its proper divisors (1).

9107989721 is an equidigital number, since it uses as much as digits as its factorization.

9107989721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 571536, while the sum is 53.

The square root of 9107989721 is about 95435.7884705732. The cubic root of 9107989721 is about 2088.3703114956.

The spelling of 9107989721 in words is "nine billion, one hundred seven million, nine hundred eighty-nine thousand, seven hundred twenty-one".