809440 has 24 divisors (see below), whose sum is σ = 1912680. Its totient is φ = 323712.

The previous prime is 809437. The next prime is 809443. The reversal of 809440 is 44908.

It is an interprime number because it is at equal distance from previous prime (809437) and next prime (809443).

It is a super-2 number, since 2×809440² = 1310386227200, which contains 22 as substring.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (809443) 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, 2370 + ... + 2689.

It is an arithmetic number, because the mean of its divisors is an integer number (79695).

2⁸⁰⁹⁴⁴⁰ is an apocalyptic number.

809440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

809440 is an abundant number, since it is smaller than the sum of its proper divisors (1103240).

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

809440 is a wasteful number, since it uses less digits than its factorization.

809440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5074 (or 5066 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 809440 is about 899.6888350980. The cubic root of 809440 is about 93.1954881248.

The spelling of 809440 in words is "eight hundred nine thousand, four hundred forty".