21303220321 has 2 divisors, whose sum is σ = 21303220322. Its totient is φ = 21303220320.

The previous prime is 21303220291. The next prime is 21303220339. The reversal of 21303220321 is 12302230312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13945011921 + 7358208400 = 118089^2 + 85780^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303220321 - 2¹⁵ = 21303187553 is a prime.

It is not a weakly prime, because it can be changed into another prime (21303220021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651610160 + 10651610161.

It is an arithmetic number, because the mean of its divisors is an integer number (10651610161).

Almost surely, 2^21303220321 is an apocalyptic number.

It is an amenable number.

21303220321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303220321 is an equidigital number, since it uses as much as digits as its factorization.

21303220321 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 21303220321 its reverse (12302230312), we get a palindrome (33605450633).

Subtracting from 21303220321 its reverse (12302230312), we obtain a palindrome (9000990009).

The spelling of 21303220321 in words is "twenty-one billion, three hundred three million, two hundred twenty thousand, three hundred twenty-one".