9685912721 has 4 divisors (see below), whose sum is σ = 9686244672. Its totient is φ = 9685580772.

The previous prime is 9685912699. The next prime is 9685912723. The reversal of 9685912721 is 1272195869.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9685912721 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9685912721.

It is not an unprimeable number, because it can be changed into a prime (9685912723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117485 + ... + 182138.

It is an arithmetic number, because the mean of its divisors is an integer number (2421561168).

Almost surely, 2^9685912721 is an apocalyptic number.

It is an amenable number.

9685912721 is a deficient number, since it is larger than the sum of its proper divisors (331951).

9685912721 is a wasteful number, since it uses less digits than its factorization.

9685912721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331950.

The product of its digits is 544320, while the sum is 50.

The square root of 9685912721 is about 98417.0347094445. The cubic root of 9685912721 is about 2131.6383114338.

The spelling of 9685912721 in words is "nine billion, six hundred eighty-five million, nine hundred twelve thousand, seven hundred twenty-one".