21231233321 has 2 divisors, whose sum is σ = 21231233322. Its totient is φ = 21231233320.

The previous prime is 21231233311. The next prime is 21231233333. The reversal of 21231233321 is 12333213212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18390343321 + 2840890000 = 135611^2 + 53300^2 .

It is a cyclic number.

It is not a de Polignac number, because 21231233321 - 2²² = 21227039017 is a prime.

It is a super-3 number, since 3×21231233321³ (a number of 32 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21231233311) 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 as a sum of consecutive naturals, namely, 10615616660 + 10615616661.

It is an arithmetic number, because the mean of its divisors is an integer number (10615616661).

Almost surely, 2^21231233321 is an apocalyptic number.

It is an amenable number.

21231233321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231233321 is an equidigital number, since it uses as much as digits as its factorization.

21231233321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 23.

Adding to 21231233321 its reverse (12333213212), we get a palindrome (33564446533).

The spelling of 21231233321 in words is "twenty-one billion, two hundred thirty-one million, two hundred thirty-three thousand, three hundred twenty-one".