1003821 has 16 divisors (see below), whose sum is σ = 1647744. Its totient is φ = 529344.

The previous prime is 1003819. The next prime is 1003841. The reversal of 1003821 is 1283001.

It is a happy number.

It is not a de Polignac number, because 1003821 - 2¹ = 1003819 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1003821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1003841) 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 15 ways as a sum of consecutive naturals, for example, 1566 + ... + 2111.

It is an arithmetic number, because the mean of its divisors is an integer number (102984).

2^1003821 is an apocalyptic number.

It is an amenable number.

1003821 is a deficient number, since it is larger than the sum of its proper divisors (643923).

1003821 is a wasteful number, since it uses less digits than its factorization.

1003821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3700.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1003821 is about 1001.9086784732. The cubic root of 1003821 is about 100.1272047875.

Adding to 1003821 its reverse (1283001), we get a palindrome (2286822).

The spelling of 1003821 in words is "one million, three thousand, eight hundred twenty-one".