813209 has 2 divisors, whose sum is σ = 813210. Its totient is φ = 813208.

The previous prime is 813203. The next prime is 813217. The reversal of 813209 is 902318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 774400 + 38809 = 880^2 + 197^2 .

It is a cyclic number.

It is not a de Polignac number, because 813209 - 2¹⁶ = 747673 is a prime.

It is a super-3 number, since 3×813209³ = 1613346993330264987, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (813203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406604 + 406605.

It is an arithmetic number, because the mean of its divisors is an integer number (406605).

2⁸¹³²⁰⁹ is an apocalyptic number.

It is an amenable number.

813209 is a deficient number, since it is larger than the sum of its proper divisors (1).

813209 is an equidigital number, since it uses as much as digits as its factorization.

813209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 813209 is about 901.7810155465. The cubic root of 813209 is about 93.3399130849.

The spelling of 813209 in words is "eight hundred thirteen thousand, two hundred nine".