13021220221 has 2 divisors, whose sum is σ = 13021220222. Its totient is φ = 13021220220.

The previous prime is 13021220143. The next prime is 13021220321. The reversal of 13021220221 is 12202212031.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8463080025 + 4558140196 = 91995^2 + 67514^2 .

It is a cyclic number.

It is not a de Polignac number, because 13021220221 - 2²⁷ = 12887002493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13021220195 and 13021220204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13021220321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6510610110 + 6510610111.

It is an arithmetic number, because the mean of its divisors is an integer number (6510610111).

Almost surely, 2^13021220221 is an apocalyptic number.

It is an amenable number.

13021220221 is a deficient number, since it is larger than the sum of its proper divisors (1).

13021220221 is an equidigital number, since it uses as much as digits as its factorization.

13021220221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 13021220221 its reverse (12202212031), we get a palindrome (25223432252).

The spelling of 13021220221 in words is "thirteen billion, twenty-one million, two hundred twenty thousand, two hundred twenty-one".