9666839021 has 6 divisors (see below), whose sum is σ = 11245098510. Its totient is φ = 8285861976.

The previous prime is 9666839009. The next prime is 9666839071. The reversal of 9666839021 is 1209386669.

It can be written as a sum of positive squares in only one way, i.e., 9156576100 + 510262921 = 95690^2 + 22589^2 .

It is not a de Polignac number, because 9666839021 - 2⁶ = 9666838957 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9666839071) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 98641166 + ... + 98641263.

It is an arithmetic number, because the mean of its divisors is an integer number (1874183085).

Almost surely, 2^9666839021 is an apocalyptic number.

It is an amenable number.

9666839021 is a deficient number, since it is larger than the sum of its proper divisors (1578259489).

9666839021 is a wasteful number, since it uses less digits than its factorization.

9666839021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197282443 (or 197282436 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 50.

The square root of 9666839021 is about 98320.0845249840. The cubic root of 9666839021 is about 2130.2381698601.

The spelling of 9666839021 in words is "nine billion, six hundred sixty-six million, eight hundred thirty-nine thousand, twenty-one".