9989769521 has 8 divisors (see below), whose sum is σ = 10032836424. Its totient is φ = 9946782720.

The previous prime is 9989769497. The next prime is 9989769523. The reversal of 9989769521 is 1259679899.

It can be written as a sum of positive squares in 4 ways, for example, as 554367025 + 9435402496 = 23545^2 + 97136^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9989769521 - 2³⁰ = 8916027697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (9989769523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 236981 + ... + 275933.

It is an arithmetic number, because the mean of its divisors is an integer number (1254104553).

Almost surely, 2^9989769521 is an apocalyptic number.

It is an amenable number.

9989769521 is a deficient number, since it is larger than the sum of its proper divisors (43066903).

9989769521 is a wasteful number, since it uses less digits than its factorization.

9989769521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40051.

The product of its digits is 22044960, while the sum is 65.

The square root of 9989769521 is about 99948.8345154660. The cubic root of 9989769521 is about 2153.6997427177.

The spelling of 9989769521 in words is "nine billion, nine hundred eighty-nine million, seven hundred sixty-nine thousand, five hundred twenty-one".