806440 has 16 divisors (see below), whose sum is σ = 1814580. Its totient is φ = 322560.

The previous prime is 806389. The next prime is 806447. The reversal of 806440 is 44608.

It can be written as a sum of positive squares in 2 ways, for example, as 806404 + 36 = 898^2 + 6^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 806440.

It is not an unprimeable number, because it can be changed into a prime (806447) 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, 10041 + ... + 10120.

2⁸⁰⁶⁴⁴⁰ is an apocalyptic number.

It is an amenable number.

806440 is an abundant number, since it is smaller than the sum of its proper divisors (1008140).

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

806440 is a wasteful number, since it uses less digits than its factorization.

806440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20172 (or 20168 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 806440 is about 898.0200443197. The cubic root of 806440 is about 93.0802098318.

The spelling of 806440 in words is "eight hundred six thousand, four hundred forty".