1004021221 has 6 divisors (see below), whose sum is σ = 1167943110. Its totient is φ = 860589576.

The previous prime is 1004021219. The next prime is 1004021257. The reversal of 1004021221 is 1221204001.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 972504225 + 31516996 = 31185^2 + 5614^2 .

It is not a de Polignac number, because 1004021221 - 2¹ = 1004021219 is a prime.

It is a super-2 number, since 2×1004021221² = 2016117224436661682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1004021261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10245066 + ... + 10245163.

It is an arithmetic number, because the mean of its divisors is an integer number (194657185).

Almost surely, 2^1004021221 is an apocalyptic number.

It is an amenable number.

1004021221 is a deficient number, since it is larger than the sum of its proper divisors (163921889).

1004021221 is an equidigital number, since it uses as much as digits as its factorization.

1004021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20490243 (or 20490236 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1004021221 is about 31686.2938981510. The cubic root of 1004021221 is about 1001.3386143122.

Adding to 1004021221 its reverse (1221204001), we get a palindrome (2225225222).

The spelling of 1004021221 in words is "one billion, four million, twenty-one thousand, two hundred twenty-one".