9866664109521 has 48 divisors (see below), whose sum is σ = 14597477856000. Its totient is φ = 6420191880960.

The previous prime is 9866664109507. The next prime is 9866664109597. The reversal of 9866664109521 is 1259014666689.

It is not a de Polignac number, because 9866664109521 - 2¹⁷ = 9866663978449 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9866664109321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 365675851 + ... + 365702831.

It is an arithmetic number, because the mean of its divisors is an integer number (304114122000).

Almost surely, 2^{9866664109521} is an apocalyptic number.

It is an amenable number.

9866664109521 is a deficient number, since it is larger than the sum of its proper divisors (4730813746479).

9866664109521 is a wasteful number, since it uses less digits than its factorization.

9866664109521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32934 (or 32931 counting only the distinct ones).

The product of its (nonzero) digits is 33592320, while the sum is 63.

The spelling of 9866664109521 in words is "nine trillion, eight hundred sixty-six billion, six hundred sixty-four million, one hundred nine thousand, five hundred twenty-one".