720716617021 has 2 divisors, whose sum is σ = 720716617022. Its totient is φ = 720716617020.

The previous prime is 720716617009. The next prime is 720716617043. The reversal of 720716617021 is 120716617027.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 656770851396 + 63945765625 = 810414^2 + 252875^2 .

It is a cyclic number.

It is not a de Polignac number, because 720716617021 - 2¹⁵ = 720716584253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (720716617421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360358308510 + 360358308511.

It is an arithmetic number, because the mean of its divisors is an integer number (360358308511).

Almost surely, 2^720716617021 is an apocalyptic number.

It is an amenable number.

720716617021 is a deficient number, since it is larger than the sum of its proper divisors (1).

720716617021 is an equidigital number, since it uses as much as digits as its factorization.

720716617021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 49392, while the sum is 40.

The spelling of 720716617021 in words is "seven hundred twenty billion, seven hundred sixteen million, six hundred seventeen thousand, twenty-one".