1840644 has 120 divisors (see below), whose sum is σ = 5691840. Its totient is φ = 513216.

The previous prime is 1840633. The next prime is 1840649. The reversal of 1840644 is 4460481.

1840644 is a `hidden beast` number, since 18 + 4 + 0 + 644 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1840649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 80017 + ... + 80039.

It is an arithmetic number, because the mean of its divisors is an integer number (47432).

2^1840644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1840644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2845920).

1840644 is an abundant number, since it is smaller than the sum of its proper divisors (3851196).

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

1840644 is a wasteful number, since it uses less digits than its factorization.

1840644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 1840644 is about 1356.7033574072. The cubic root of 1840644 is about 122.5528079969.

The spelling of 1840644 in words is "one million, eight hundred forty thousand, six hundred forty-four".