9778997321 has 2 divisors, whose sum is σ = 9778997322. Its totient is φ = 9778997320.

The previous prime is 9778997233. The next prime is 9778997351. The reversal of 9778997321 is 1237998779.

9778997321 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., 6171673600 + 3607323721 = 78560^2 + 60061^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9778997321 is a prime.

It is not a weakly prime, because it can be changed into another prime (9778997351) 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, 4889498660 + 4889498661.

It is an arithmetic number, because the mean of its divisors is an integer number (4889498661).

Almost surely, 2^9778997321 is an apocalyptic number.

It is an amenable number.

9778997321 is a deficient number, since it is larger than the sum of its proper divisors (1).

9778997321 is an equidigital number, since it uses as much as digits as its factorization.

9778997321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12002256, while the sum is 62.

The square root of 9778997321 is about 98888.8129213816. The cubic root of 9778997321 is about 2138.4451191820.

The spelling of 9778997321 in words is "nine billion, seven hundred seventy-eight million, nine hundred ninety-seven thousand, three hundred twenty-one".