561720750721 has 8 divisors (see below), whose sum is σ = 605096691584. Its totient is φ = 518368617360.

The previous prime is 561720750719. The next prime is 561720750803. The reversal of 561720750721 is 127057027165.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 561720750721 - 2¹ = 561720750719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561720700721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5902851 + ... + 5997256.

It is an arithmetic number, because the mean of its divisors is an integer number (75637086448).

Almost surely, 2^561720750721 is an apocalyptic number.

It is an amenable number.

561720750721 is a deficient number, since it is larger than the sum of its proper divisors (43375940863).

561720750721 is a wasteful number, since it uses less digits than its factorization.

561720750721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11903751.

The product of its (nonzero) digits is 205800, while the sum is 43.

Adding to 561720750721 its reverse (127057027165), we get a palindrome (688777777886).

The spelling of 561720750721 in words is "five hundred sixty-one billion, seven hundred twenty million, seven hundred fifty thousand, seven hundred twenty-one".