9988438561 has 2 divisors, whose sum is σ = 9988438562. Its totient is φ = 9988438560.

The previous prime is 9988438541. The next prime is 9988438601. The reversal of 9988438561 is 1658348899.

9988438561 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., 9925140625 + 63297936 = 99625^2 + 7956^2 .

It is a cyclic number.

It is not a de Polignac number, because 9988438561 - 2⁷ = 9988438433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9988438561.

It is not a weakly prime, because it can be changed into another prime (9988438541) 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, 4994219280 + 4994219281.

It is an arithmetic number, because the mean of its divisors is an integer number (4994219281).

Almost surely, 2^9988438561 is an apocalyptic number.

It is an amenable number.

9988438561 is a deficient number, since it is larger than the sum of its proper divisors (1).

9988438561 is an equidigital number, since it uses as much as digits as its factorization.

9988438561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14929920, while the sum is 61.

The square root of 9988438561 is about 99942.1760869754. The cubic root of 9988438561 is about 2153.6040910107.

The spelling of 9988438561 in words is "nine billion, nine hundred eighty-eight million, four hundred thirty-eight thousand, five hundred sixty-one".