722309 has 6 divisors (see below), whose sum is σ = 840294. Its totient is φ = 619080.

The previous prime is 722299. The next prime is 722311. The reversal of 722309 is 903227.

It can be written as a sum of positive squares in only one way, i.e., 717409 + 4900 = 847^2 + 70^2 .

It is a de Polignac number, because none of the positive numbers 2^k-722309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (722369) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7322 + ... + 7419.

It is an arithmetic number, because the mean of its divisors is an integer number (140049).

2⁷²²³⁰⁹ is an apocalyptic number.

It is an amenable number.

722309 is a deficient number, since it is larger than the sum of its proper divisors (117985).

722309 is a wasteful number, since it uses less digits than its factorization.

722309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14755 (or 14748 counting only the distinct ones).

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 722309 is about 849.8876396324. The cubic root of 722309 is about 89.7238034670.

The spelling of 722309 in words is "seven hundred twenty-two thousand, three hundred nine".