1821841 has 4 divisors (see below), whose sum is σ = 2082112. Its totient is φ = 1561572.

The previous prime is 1821821. The next prime is 1821847. The reversal of 1821841 is 1481281.

1821841 = T₄₀₆ + T₄₀₇ + ... + T₄₂₆.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1821841 - 2⁷ = 1821713 is a prime.

It is a Duffinian 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 in 3 ways as a sum of consecutive naturals, for example, 130125 + ... + 130138.

It is an arithmetic number, because the mean of its divisors is an integer number (520528).

2^1821841 is an apocalyptic number.

It is an amenable number.

1821841 is a deficient number, since it is larger than the sum of its proper divisors (260271).

1821841 is an equidigital number, since it uses as much as digits as its factorization.

1821841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 260270.

The product of its digits is 512, while the sum is 25.

The square root of 1821841 is about 1349.7559038582. The cubic root of 1821841 is about 122.1340683282.

It can be divided in two parts, 1821 and 841, that added together give a palindrome (2662).

The spelling of 1821841 in words is "one million, eight hundred twenty-one thousand, eight hundred forty-one".