18000840 has 128 divisors (see below), whose sum is σ = 63504000. Its totient is φ = 4024320.

The previous prime is 18000821. The next prime is 18000869. The reversal of 18000840 is 4800081.

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 31 ways as a sum of consecutive naturals, for example, 16636 + ... + 17684.

It is an arithmetic number, because the mean of its divisors is an integer number (496125).

Almost surely, 2^18000840 is an apocalyptic number.

18000840 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 18000840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31752000).

18000840 is an abundant number, since it is smaller than the sum of its proper divisors (45503160).

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

18000840 is a wasteful number, since it uses less digits than its factorization.

18000840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1087 (or 1083 counting only the distinct ones).

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

The square root of 18000840 is about 4242.7396809137. The cubic root of 18000840 is about 262.0782160663.

The spelling of 18000840 in words is "eighteen million, eight hundred forty", and thus it is an aban number.