9656613761721 has 16 divisors (see below), whose sum is σ = 13009375447488. Its totient is φ = 6370809062400.

The previous prime is 9656613761671. The next prime is 9656613761747. The reversal of 9656613761721 is 1271673166569.

It is not a de Polignac number, because 9656613761721 - 2¹⁵ = 9656613728953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9656613761321) 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 15 ways as a sum of consecutive naturals, for example, 1828806 + ... + 4760016.

It is an arithmetic number, because the mean of its divisors is an integer number (813085965468).

Almost surely, 2^{9656613761721} is an apocalyptic number.

It is an amenable number.

9656613761721 is a deficient number, since it is larger than the sum of its proper divisors (3352761685767).

9656613761721 is a wasteful number, since it uses less digits than its factorization.

9656613761721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2942632.

The product of its digits is 17146080, while the sum is 60.

The spelling of 9656613761721 in words is "nine trillion, six hundred fifty-six billion, six hundred thirteen million, seven hundred sixty-one thousand, seven hundred twenty-one".