809940 has 24 divisors (see below), whose sum is σ = 2268000. Its totient is φ = 215968.

The previous prime is 809929. The next prime is 809981. The reversal of 809940 is 49908.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 809898 and 809907.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6690 + ... + 6809.

It is an arithmetic number, because the mean of its divisors is an integer number (94500).

2⁸⁰⁹⁹⁴⁰ is an apocalyptic number.

It is an amenable number.

809940 is an abundant number, since it is smaller than the sum of its proper divisors (1458060).

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

809940 is a wasteful number, since it uses less digits than its factorization.

809940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13511 (or 13509 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 809940 is about 899.9666660494. The cubic root of 809940 is about 93.2146734681.

The spelling of 809940 in words is "eight hundred nine thousand, nine hundred forty".