1819840 has 84 divisors (see below), whose sum is σ = 4864608. Its totient is φ = 647680.

The previous prime is 1819819. The next prime is 1819841. The reversal of 1819840 is 489181.

It is not an unprimeable number, because it can be changed into a prime (1819841) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38697 + ... + 38743.

It is an arithmetic number, because the mean of its divisors is an integer number (57912).

2^1819840 is an apocalyptic number.

1819840 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 1819840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2432304).

1819840 is an abundant number, since it is smaller than the sum of its proper divisors (3044768).

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

1819840 is a wasteful number, since it uses less digits than its factorization.

1819840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 1819840 is about 1349.0144550745. The cubic root of 1819840 is about 122.0893370555.

The spelling of 1819840 in words is "one million, eight hundred nineteen thousand, eight hundred forty".