1663844 has 36 divisors (see below), whose sum is σ = 3653244. Its totient is φ = 657216.

The previous prime is 1663813. The next prime is 1663861. The reversal of 1663844 is 4483661.

It can be written as a sum of positive squares in 2 ways, for example, as 313600 + 1350244 = 560^2 + 1162^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1663844.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2222 + ... + 2874.

It is an arithmetic number, because the mean of its divisors is an integer number (101479).

2^1663844 is an apocalyptic number.

1663844 is a gapful number since it is divisible by the number (14) 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 1663844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1826622).

1663844 is an abundant number, since it is smaller than the sum of its proper divisors (1989400).

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

1663844 is a wasteful number, since it uses less digits than its factorization.

1663844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 684 (or 675 counting only the distinct ones).

The product of its digits is 13824, while the sum is 32.

The square root of 1663844 is about 1289.9007713774. The cubic root of 1663844 is about 118.4961395005.

The spelling of 1663844 in words is "one million, six hundred sixty-three thousand, eight hundred forty-four".