809986 has 8 divisors (see below), whose sum is σ = 1222524. Its totient is φ = 402480.

The previous prime is 809983. The next prime is 809993. The reversal of 809986 is 689908.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 731025 + 78961 = 855^2 + 281^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (809981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 825 + ... + 1516.

2⁸⁰⁹⁹⁸⁶ is an apocalyptic number.

809986 is a deficient number, since it is larger than the sum of its proper divisors (412538).

809986 is a wasteful number, since it uses less digits than its factorization.

809986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2516.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 809986 is about 899.9922221886. The cubic root of 809986 is about 93.2164381230.

The spelling of 809986 in words is "eight hundred nine thousand, nine hundred eighty-six".