720947009 has 2 divisors, whose sum is σ = 720947010. Its totient is φ = 720947008.

The previous prime is 720946997. The next prime is 720947011. The reversal of 720947009 is 900749027.

It is a happy number.

720947009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 646176400 + 74770609 = 25420^2 + 8647^2 .

It is a cyclic number.

It is not a de Polignac number, because 720947009 - 2²⁰ = 719898433 is a prime.

It is a Sophie Germain prime.

Together with 720947011, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (720941009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360473504 + 360473505.

It is an arithmetic number, because the mean of its divisors is an integer number (360473505).

Almost surely, 2^720947009 is an apocalyptic number.

It is an amenable number.

720947009 is a deficient number, since it is larger than the sum of its proper divisors (1).

720947009 is an equidigital number, since it uses as much as digits as its factorization.

720947009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 720947009 is about 26850.4564020800. The cubic root of 720947009 is about 896.6737336928.

The spelling of 720947009 in words is "seven hundred twenty million, nine hundred forty-seven thousand, nine".