13221012121 has 2 divisors, whose sum is σ = 13221012122. Its totient is φ = 13221012120.

The previous prime is 13221012097. The next prime is 13221012143. The reversal of 13221012121 is 12121012231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12501699721 + 719312400 = 111811^2 + 26820^2 .

It is a cyclic number.

It is not a de Polignac number, because 13221012121 - 2⁵ = 13221012089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13221012095 and 13221012104.

It is not a weakly prime, because it can be changed into another prime (13221012821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6610506060 + 6610506061.

It is an arithmetic number, because the mean of its divisors is an integer number (6610506061).

Almost surely, 2^13221012121 is an apocalyptic number.

It is an amenable number.

13221012121 is a deficient number, since it is larger than the sum of its proper divisors (1).

13221012121 is an equidigital number, since it uses as much as digits as its factorization.

13221012121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 13221012121 its reverse (12121012231), we get a palindrome (25342024352).

The spelling of 13221012121 in words is "thirteen billion, two hundred twenty-one million, twelve thousand, one hundred twenty-one".