9989765551 has 2 divisors, whose sum is σ = 9989765552. Its totient is φ = 9989765550.

The previous prime is 9989765549. The next prime is 9989765557. The reversal of 9989765551 is 1555679899.

9989765551 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is an emirp because it is prime and its reverse (1555679899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9989765551 - 2¹ = 9989765549 is a prime.

Together with 9989765549, 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 (9989765557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4994882775 + 4994882776.

It is an arithmetic number, because the mean of its divisors is an integer number (4994882776).

Almost surely, 2^9989765551 is an apocalyptic number.

9989765551 is a deficient number, since it is larger than the sum of its proper divisors (1).

9989765551 is an equidigital number, since it uses as much as digits as its factorization.

9989765551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30618000, while the sum is 64.

The square root of 9989765551 is about 99948.8146553024. The cubic root of 9989765551 is about 2153.6994574195.

The spelling of 9989765551 in words is "nine billion, nine hundred eighty-nine million, seven hundred sixty-five thousand, five hundred fifty-one".