2003821 has 4 divisors (see below), whose sum is σ = 2007072. Its totient is φ = 2000572.

The previous prime is 2003819. The next prime is 2003839. The reversal of 2003821 is 1283002.

It is a happy number.

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 2003821 - 2¹ = 2003819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2003795 and 2003804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2003801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 385 + ... + 2038.

It is an arithmetic number, because the mean of its divisors is an integer number (501768).

2^2003821 is an apocalyptic number.

It is an amenable number.

2003821 is a deficient number, since it is larger than the sum of its proper divisors (3251).

2003821 is an equidigital number, since it uses as much as digits as its factorization.

2003821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3250.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 2003821 is about 1415.5638452574. The cubic root of 2003821 is about 126.0722899189.

Adding to 2003821 its reverse (1283002), we get a palindrome (3286823).

The spelling of 2003821 in words is "two million, three thousand, eight hundred twenty-one".