21333020321 has 4 divisors (see below), whose sum is σ = 21342135444. Its totient is φ = 21323905200.

The previous prime is 21333020311. The next prime is 21333020351. The reversal of 21333020321 is 12302033312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11711568400 + 9621451921 = 108220^2 + 98089^2 .

It is a cyclic number.

It is not a de Polignac number, because 21333020321 - 2¹⁸ = 21332758177 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21333020293 and 21333020302.

It is not an unprimeable number, because it can be changed into a prime (21333020311) 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 in 3 ways as a sum of consecutive naturals, for example, 4554050 + ... + 4558731.

It is an arithmetic number, because the mean of its divisors is an integer number (5335533861).

Almost surely, 2^21333020321 is an apocalyptic number.

It is an amenable number.

21333020321 is a deficient number, since it is larger than the sum of its proper divisors (9115123).

21333020321 is an equidigital number, since it uses as much as digits as its factorization.

21333020321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9115122.

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 21333020321 its reverse (12302033312), we get a palindrome (33635053633).

The spelling of 21333020321 in words is "twenty-one billion, three hundred thirty-three million, twenty thousand, three hundred twenty-one".