9721044209709 has 72 divisors (see below), whose sum is σ = 16386982859520. Its totient is φ = 5553064224288.

The previous prime is 9721044209699. The next prime is 9721044209731. The reversal of 9721044209709 is 9079024401279.

9721044209709 is a `hidden beast` number, since 97 + 21 + 0 + 442 + 0 + 97 + 0 + 9 = 666.

It is not a de Polignac number, because 9721044209709 - 2⁷ = 9721044209581 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9721044209309) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 561025804 + ... + 561043130.

It is an arithmetic number, because the mean of its divisors is an integer number (227596984160).

Almost surely, 2^{9721044209709} is an apocalyptic number.

It is an amenable number.

9721044209709 is a deficient number, since it is larger than the sum of its proper divisors (6665938649811).

9721044209709 is an equidigital number, since it uses as much as digits as its factorization.

9721044209709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21077 (or 21046 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 54.

The spelling of 9721044209709 in words is "nine trillion, seven hundred twenty-one billion, forty-four million, two hundred nine thousand, seven hundred nine".