720347609 has 2 divisors, whose sum is σ = 720347610. Its totient is φ = 720347608.

The previous prime is 720347591. The next prime is 720347657. The reversal of 720347609 is 906743027.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 704371600 + 15976009 = 26540^2 + 3997^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-720347609 is a prime.

It is not a weakly prime, because it can be changed into another prime (720347669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360173804 + 360173805.

It is an arithmetic number, because the mean of its divisors is an integer number (360173805).

Almost surely, 2^720347609 is an apocalyptic number.

It is an amenable number.

720347609 is a deficient number, since it is larger than the sum of its proper divisors (1).

720347609 is an equidigital number, since it uses as much as digits as its factorization.

720347609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 63504, while the sum is 38.

The square root of 720347609 is about 26839.2922596703. The cubic root of 720347609 is about 896.4251646815.

The spelling of 720347609 in words is "seven hundred twenty million, three hundred forty-seven thousand, six hundred nine".