809988 has 12 divisors (see below), whose sum is σ = 1890000. Its totient is φ = 269992.

The previous prime is 809983. The next prime is 809993. The reversal of 809988 is 889908.

It is an interprime number because it is at equal distance from previous prime (809983) and next prime (809993).

It is a tau number, because it is divible by the number of its divisors (12).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a plaindrome in base 13.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 809988.

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, 33738 + ... + 33761.

It is an arithmetic number, because the mean of its divisors is an integer number (157500).

2⁸⁰⁹⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

809988 is an abundant number, since it is smaller than the sum of its proper divisors (1080012).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

809988 is a wasteful number, since it uses less digits than its factorization.

809988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67506 (or 67504 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 42.

The square root of 809988 is about 899.9933333086. The cubic root of 809988 is about 93.2165148456.

The spelling of 809988 in words is "eight hundred nine thousand, nine hundred eighty-eight".