1323021221 has 4 divisors (see below), whose sum is σ = 1323098700. Its totient is φ = 1322943744.

The previous prime is 1323021211. The next prime is 1323021229. The reversal of 1323021221 is 1221203231.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1221203231 = 10159 ⋅120209.

It can be written as a sum of positive squares in 2 ways, for example, as 634536100 + 688485121 = 25190^2 + 26239^2 .

It is a cyclic number.

It is not a de Polignac number, because 1323021221 - 2¹⁰ = 1323020197 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1323021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1323021229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 626 + ... + 51443.

It is an arithmetic number, because the mean of its divisors is an integer number (330774675).

Almost surely, 2^1323021221 is an apocalyptic number.

It is an amenable number.

1323021221 is a deficient number, since it is larger than the sum of its proper divisors (77479).

1323021221 is an equidigital number, since it uses as much as digits as its factorization.

1323021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77478.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 1323021221 is about 36373.3586708734. The cubic root of 1323021221 is about 1097.7975825240.

Adding to 1323021221 its reverse (1221203231), we get a palindrome (2544224452).

The spelling of 1323021221 in words is "one billion, three hundred twenty-three million, twenty-one thousand, two hundred twenty-one".