9666633090721 has 4 divisors (see below), whose sum is σ = 9666652227652. Its totient is φ = 9666613953792.

The previous prime is 9666633090703. The next prime is 9666633090739. The reversal of 9666633090721 is 1270903366669.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (9666633090703) and next prime (9666633090739).

It can be written as a sum of positive squares in 2 ways, for example, as 3931872581025 + 5734760509696 = 1982895^2 + 2394736^2 .

It is a cyclic number.

It is not a de Polignac number, because 9666633090721 - 2¹³ = 9666633082529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9666633090781) 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 3 ways as a sum of consecutive naturals, for example, 8789640 + ... + 9828073.

It is an arithmetic number, because the mean of its divisors is an integer number (2416663056913).

Almost surely, 2^{9666633090721} is an apocalyptic number.

It is an amenable number.

9666633090721 is a deficient number, since it is larger than the sum of its proper divisors (19136931).

9666633090721 is a wasteful number, since it uses less digits than its factorization.

9666633090721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19136930.

The product of its (nonzero) digits is 13226976, while the sum is 58.

The spelling of 9666633090721 in words is "nine trillion, six hundred sixty-six billion, six hundred thirty-three million, ninety thousand, seven hundred twenty-one".