21403330321 has 2 divisors, whose sum is σ = 21403330322. Its totient is φ = 21403330320.

The previous prime is 21403330303. The next prime is 21403330357. The reversal of 21403330321 is 12303330412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16106401921 + 5296928400 = 126911^2 + 72780^2 .

It is a cyclic number.

It is not a de Polignac number, because 21403330321 - 2⁹ = 21403329809 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21403330292 and 21403330301.

It is not a weakly prime, because it can be changed into another prime (21403330381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10701665160 + 10701665161.

It is an arithmetic number, because the mean of its divisors is an integer number (10701665161).

Almost surely, 2^21403330321 is an apocalyptic number.

It is an amenable number.

21403330321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21403330321 is an equidigital number, since it uses as much as digits as its factorization.

21403330321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1296, while the sum is 22.

Adding to 21403330321 its reverse (12303330412), we get a palindrome (33706660733).

Subtracting from 21403330321 its reverse (12303330412), we obtain a palindrome (9099999909).

The spelling of 21403330321 in words is "twenty-one billion, four hundred three million, three hundred thirty thousand, three hundred twenty-one".