21323221321 has 2 divisors, whose sum is σ = 21323221322. Its totient is φ = 21323221320.

The previous prime is 21323221313. The next prime is 21323221349. The reversal of 21323221321 is 12312232312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20857136400 + 466084921 = 144420^2 + 21589^2 .

It is a cyclic number.

It is not a de Polignac number, because 21323221321 - 2³ = 21323221313 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21323221292 and 21323221301.

It is not a weakly prime, because it can be changed into another prime (21323221301) 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, 10661610660 + 10661610661.

It is an arithmetic number, because the mean of its divisors is an integer number (10661610661).

Almost surely, 2^21323221321 is an apocalyptic number.

It is an amenable number.

21323221321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323221321 is an equidigital number, since it uses as much as digits as its factorization.

21323221321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 22.

Adding to 21323221321 its reverse (12312232312), we get a palindrome (33635453633).

The spelling of 21323221321 in words is "twenty-one billion, three hundred twenty-three million, two hundred twenty-one thousand, three hundred twenty-one".