21432110321 has 2 divisors, whose sum is σ = 21432110322. Its totient is φ = 21432110320.

The previous prime is 21432110317. The next prime is 21432110389. The reversal of 21432110321 is 12301123412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19730135296 + 1701975025 = 140464^2 + 41255^2 .

It is a cyclic number.

It is not a de Polignac number, because 21432110321 - 2² = 21432110317 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21432110293 and 21432110302.

It is not a weakly prime, because it can be changed into another prime (21432119321) 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, 10716055160 + 10716055161.

It is an arithmetic number, because the mean of its divisors is an integer number (10716055161).

Almost surely, 2^21432110321 is an apocalyptic number.

It is an amenable number.

21432110321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21432110321 is an equidigital number, since it uses as much as digits as its factorization.

21432110321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21432110321 its reverse (12301123412), we get a palindrome (33733233733).

The spelling of 21432110321 in words is "twenty-one billion, four hundred thirty-two million, one hundred ten thousand, three hundred twenty-one".