1800840 has 64 divisors (see below), whose sum is σ = 5544000. Its totient is φ = 467712.

The previous prime is 1800833. The next prime is 1800853. The reversal of 1800840 is 480081.

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 15 ways as a sum of consecutive naturals, for example, 4986 + ... + 5334.

It is an arithmetic number, because the mean of its divisors is an integer number (86625).

2^1800840 is an apocalyptic number.

1800840 is a gapful number since it is divisible by the number (10) 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 1800840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2772000).

1800840 is an abundant number, since it is smaller than the sum of its proper divisors (3743160).

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

1800840 is a wasteful number, since it uses less digits than its factorization.

1800840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406 (or 402 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 1800840 is about 1341.9537995028. The cubic root of 1800840 is about 121.6629593750.

The spelling of 1800840 in words is "one million, eight hundred thousand, eight hundred forty".