1821844 has 6 divisors (see below), whose sum is σ = 3188234. Its totient is φ = 910920.

The previous prime is 1821821. The next prime is 1821847. The reversal of 1821844 is 4481281.

It can be written as a sum of positive squares in only one way, i.e., 1795600 + 26244 = 1340^2 + 162^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821847) by changing a digit.

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 as a sum of consecutive naturals, namely, 227727 + ... + 227734.

2^1821844 is an apocalyptic number.

It is an amenable number.

1821844 is a deficient number, since it is larger than the sum of its proper divisors (1366390).

1821844 is a wasteful number, since it uses less digits than its factorization.

1821844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455465 (or 455463 counting only the distinct ones).

The product of its digits is 2048, while the sum is 28.

The square root of 1821844 is about 1349.7570151698. The cubic root of 1821844 is about 122.1341353670.

The spelling of 1821844 in words is "one million, eight hundred twenty-one thousand, eight hundred forty-four".