809943 has 4 divisors (see below), whose sum is σ = 1079928. Its totient is φ = 539960.

The previous prime is 809929. The next prime is 809981. The reversal of 809943 is 349908.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 809943 - 2¹⁰ = 808919 is a prime.

It is a D-number.

809943 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 809943.

It is not an unprimeable number, because it can be changed into a prime (809903) 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 in 3 ways as a sum of consecutive naturals, for example, 134988 + ... + 134993.

It is an arithmetic number, because the mean of its divisors is an integer number (269982).

2⁸⁰⁹⁹⁴³ is an apocalyptic number.

809943 is a deficient number, since it is larger than the sum of its proper divisors (269985).

809943 is a wasteful number, since it uses less digits than its factorization.

809943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269984.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 809943 is about 899.9683327762. The cubic root of 809943 is about 93.2147885563.

The spelling of 809943 in words is "eight hundred nine thousand, nine hundred forty-three".