9928328981 has 2 divisors, whose sum is σ = 9928328982. Its totient is φ = 9928328980.

The previous prime is 9928328957. The next prime is 9928328999. The reversal of 9928328981 is 1898238299.

9928328981 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., 9928328881 + 100 = 99641^2 + 10^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9928328981 is a prime.

It is a super-2 number, since 2×9928328981² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 9928328981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9928328941) 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, 4964164490 + 4964164491.

It is an arithmetic number, because the mean of its divisors is an integer number (4964164491).

Almost surely, 2^9928328981 is an apocalyptic number.

It is an amenable number.

9928328981 is a deficient number, since it is larger than the sum of its proper divisors (1).

9928328981 is an equidigital number, since it uses as much as digits as its factorization.

9928328981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4478976, while the sum is 59.

The square root of 9928328981 is about 99641.0005018015. Note that the first 3 decimals coincide. The cubic root of 9928328981 is about 2149.2753267824.

The spelling of 9928328981 in words is "nine billion, nine hundred twenty-eight million, three hundred twenty-eight thousand, nine hundred eighty-one".