1808840 has 32 divisors (see below), whose sum is σ = 4440960. Its totient is φ = 657600.

The previous prime is 1808839. The next prime is 1808843. The reversal of 1808840 is 488081.

It is not an unprimeable number, because it can be changed into a prime (1808843) by changing a digit.

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, 1616 + ... + 2495.

It is an arithmetic number, because the mean of its divisors is an integer number (138780).

2^1808840 is an apocalyptic number.

1808840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1808840 is an abundant number, since it is smaller than the sum of its proper divisors (2632120).

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

1808840 is a wasteful number, since it uses less digits than its factorization.

1808840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4133 (or 4129 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 29.

The square root of 1808840 is about 1344.9312250074. The cubic root of 1808840 is about 121.8428506040.

The spelling of 1808840 in words is "one million, eight hundred eight thousand, eight hundred forty".