9989884789 has 2 divisors, whose sum is σ = 9989884790. Its totient is φ = 9989884788.

The previous prime is 9989884787. The next prime is 9989884867. The reversal of 9989884789 is 9874889899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7543791025 + 2446093764 = 86855^2 + 49458^2 .

It is a cyclic number.

It is not a de Polignac number, because 9989884789 - 2¹ = 9989884787 is a prime.

Together with 9989884787, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9989884787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4994942394 + 4994942395.

It is an arithmetic number, because the mean of its divisors is an integer number (4994942395).

Almost surely, 2^9989884789 is an apocalyptic number.

It is an amenable number.

9989884789 is a deficient number, since it is larger than the sum of its proper divisors (1).

9989884789 is an equidigital number, since it uses as much as digits as its factorization.

9989884789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 752467968, while the sum is 79.

The square root of 9989884789 is about 99949.4111488407. The cubic root of 9989884789 is about 2153.7080262490.

The spelling of 9989884789 in words is "nine billion, nine hundred eighty-nine million, eight hundred eighty-four thousand, seven hundred eighty-nine".