21020443321 has 2 divisors, whose sum is σ = 21020443322. Its totient is φ = 21020443320.

The previous prime is 21020443313. The next prime is 21020443333. The reversal of 21020443321 is 12334402012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20012063296 + 1008380025 = 141464^2 + 31755^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020443321 - 2³ = 21020443313 is a prime.

It is a super-2 number, since 2×21020443321² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21020443292 and 21020443301.

It is not a weakly prime, because it can be changed into another prime (21020443021) 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, 10510221660 + 10510221661.

It is an arithmetic number, because the mean of its divisors is an integer number (10510221661).

Almost surely, 2^21020443321 is an apocalyptic number.

It is an amenable number.

21020443321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020443321 is an equidigital number, since it uses as much as digits as its factorization.

21020443321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 22.

Adding to 21020443321 its reverse (12334402012), we get a palindrome (33354845333).

The spelling of 21020443321 in words is "twenty-one billion, twenty million, four hundred forty-three thousand, three hundred twenty-one".