723409 has 2 divisors, whose sum is σ = 723410. Its totient is φ = 723408.

The previous prime is 723407. The next prime is 723413. The reversal of 723409 is 904327.

723409 is an esthetic number in base 11, because in such base its adjacent digits differ by 1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 540225 + 183184 = 735^2 + 428^2 .

It is a cyclic number.

It is not a de Polignac number, because 723409 - 2¹ = 723407 is a prime.

Together with 723407, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (723407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 361704 + 361705.

It is an arithmetic number, because the mean of its divisors is an integer number (361705).

2⁷²³⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

723409 is a deficient number, since it is larger than the sum of its proper divisors (1).

723409 is an equidigital number, since it uses as much as digits as its factorization.

723409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 723409 is about 850.5345378055. The cubic root of 723409 is about 89.7693269779.

It can be divided in two parts, 72 and 3409, that added together give a square (3481 = 59²).

The spelling of 723409 in words is "seven hundred twenty-three thousand, four hundred nine".