800509 has 2 divisors, whose sum is σ = 800510. Its totient is φ = 800508.

The previous prime is 800497. The next prime is 800519. The reversal of 800509 is 905008.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 727609 + 72900 = 853^2 + 270^2 .

It is a cyclic number.

It is not a de Polignac number, because 800509 - 2⁵ = 800477 is a prime.

It is a Chen prime.

800509 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 800509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (800519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 400254 + 400255.

It is an arithmetic number, because the mean of its divisors is an integer number (400255).

2⁸⁰⁰⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

800509 is a deficient number, since it is larger than the sum of its proper divisors (1).

800509 is an equidigital number, since it uses as much as digits as its factorization.

800509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 800509 is about 894.7116854049. The cubic root of 800509 is about 92.8514605709.

The spelling of 800509 in words is "eight hundred thousand, five hundred nine".