805440 has 56 divisors (see below), whose sum is σ = 2560320. Its totient is φ = 214528.

The previous prime is 805421. The next prime is 805451. The reversal of 805440 is 44508.

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 805440.

It is an unprimeable number.

805440 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 541 + ... + 1379.

It is an arithmetic number, because the mean of its divisors is an integer number (45720).

2⁸⁰⁵⁴⁴⁰ is an apocalyptic number.

805440 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 805440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1280160).

805440 is an abundant number, since it is smaller than the sum of its proper divisors (1754880).

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

805440 is a wasteful number, since it uses less digits than its factorization.

805440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 859 (or 849 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 805440 is about 897.4630911631. The cubic root of 805440 is about 93.0417202107.

Adding to 805440 its reverse (44508), we get a palindrome (849948).

The spelling of 805440 in words is "eight hundred five thousand, four hundred forty".