726809 has 2 divisors, whose sum is σ = 726810. Its totient is φ = 726808.

The previous prime is 726797. The next prime is 726811. The reversal of 726809 is 908627.

726809 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., 697225 + 29584 = 835^2 + 172^2 .

It is an emirp because it is prime and its reverse (908627) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 726809 - 2¹² = 722713 is a prime.

Together with 726811, it forms a pair of twin primes.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 726809.

It is not a weakly prime, because it can be changed into another prime (726839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 363404 + 363405.

It is an arithmetic number, because the mean of its divisors is an integer number (363405).

2⁷²⁶⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

726809 is a deficient number, since it is larger than the sum of its proper divisors (1).

726809 is an equidigital number, since it uses as much as digits as its factorization.

726809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 726809 is about 852.5309378550. The cubic root of 726809 is about 89.9097449103.

The spelling of 726809 in words is "seven hundred twenty-six thousand, eight hundred nine".