722509 has 2 divisors, whose sum is σ = 722510. Its totient is φ = 722508.

The previous prime is 722489. The next prime is 722521. The reversal of 722509 is 905227.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 722500 + 9 = 850^2 + 3^2 .

It is an emirp because it is prime and its reverse (905227) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 722509 - 2⁹ = 721997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (722539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 361254 + 361255.

It is an arithmetic number, because the mean of its divisors is an integer number (361255).

2⁷²²⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

722509 is a deficient number, since it is larger than the sum of its proper divisors (1).

722509 is an equidigital number, since it uses as much as digits as its factorization.

722509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 722509 is about 850.0052941012. The cubic root of 722509 is about 89.7320839050.

The spelling of 722509 in words is "seven hundred twenty-two thousand, five hundred nine".