720556913 has 2 divisors, whose sum is σ = 720556914. Its totient is φ = 720556912.

The previous prime is 720556909. The next prime is 720556933. The reversal of 720556913 is 319655027.

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., 717811264 + 2745649 = 26792^2 + 1657^2 .

It is an emirp because it is prime and its reverse (319655027) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 720556913 - 2² = 720556909 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (720556933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360278456 + 360278457.

It is an arithmetic number, because the mean of its divisors is an integer number (360278457).

Almost surely, 2^720556913 is an apocalyptic number.

It is an amenable number.

720556913 is a deficient number, since it is larger than the sum of its proper divisors (1).

720556913 is an equidigital number, since it uses as much as digits as its factorization.

720556913 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 56700, while the sum is 38.

The square root of 720556913 is about 26843.1911851032. The cubic root of 720556913 is about 896.5119779557.

The spelling of 720556913 in words is "seven hundred twenty million, five hundred fifty-six thousand, nine hundred thirteen".