1004021 has 4 divisors (see below), whose sum is σ = 1008672. Its totient is φ = 999372.

The previous prime is 1003963. The next prime is 1004027. The reversal of 1004021 is 1204001.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1204001 = 53 ⋅22717.

It is a cyclic number.

It is not a de Polignac number, because 1004021 - 2⁶ = 1003957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1004027) 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, 1985 + ... + 2438.

It is an arithmetic number, because the mean of its divisors is an integer number (252168).

2^1004021 is an apocalyptic number.

It is an amenable number.

1004021 is a deficient number, since it is larger than the sum of its proper divisors (4651).

1004021 is an equidigital number, since it uses as much as digits as its factorization.

1004021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4650.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 1004021 is about 1002.0084829980. The cubic root of 1004021 is about 100.1338540842.

Adding to 1004021 its reverse (1204001), we get a palindrome (2208022).

The spelling of 1004021 in words is "one million, four thousand, twenty-one".