21223030321 has 2 divisors, whose sum is σ = 21223030322. Its totient is φ = 21223030320.

The previous prime is 21223030303. The next prime is 21223030331. The reversal of 21223030321 is 12303032212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20761639921 + 461390400 = 144089^2 + 21480^2 .

It is a cyclic number.

It is not a de Polignac number, because 21223030321 - 2¹⁵ = 21222997553 is a prime.

It is not a weakly prime, because it can be changed into another prime (21223030331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611515160 + 10611515161.

It is an arithmetic number, because the mean of its divisors is an integer number (10611515161).

Almost surely, 2^21223030321 is an apocalyptic number.

It is an amenable number.

21223030321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21223030321 is an equidigital number, since it uses as much as digits as its factorization.

21223030321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 19.

Adding to 21223030321 its reverse (12303032212), we get a palindrome (33526062533).

The spelling of 21223030321 in words is "twenty-one billion, two hundred twenty-three million, thirty thousand, three hundred twenty-one".