805643 has 4 divisors (see below), whose sum is σ = 811200. Its totient is φ = 800088.

The previous prime is 805639. The next prime is 805687. The reversal of 805643 is 346508.

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 805643 - 2² = 805639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (805633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2555 + ... + 2852.

It is an arithmetic number, because the mean of its divisors is an integer number (202800).

2⁸⁰⁵⁶⁴³ is an apocalyptic number.

805643 is a deficient number, since it is larger than the sum of its proper divisors (5557).

805643 is a wasteful number, since it uses less digits than its factorization.

805643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5556.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 805643 is about 897.5761806109. The cubic root of 805643 is about 93.0495361799.

The spelling of 805643 in words is "eight hundred five thousand, six hundred forty-three".