13111223221 has 2 divisors, whose sum is σ = 13111223222. Its totient is φ = 13111223220.

The previous prime is 13111223219. The next prime is 13111223249. The reversal of 13111223221 is 12232211131.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12434703121 + 676520100 = 111511^2 + 26010^2 .

It is a cyclic number.

It is not a de Polignac number, because 13111223221 - 2¹ = 13111223219 is a prime.

It is a super-3 number, since 3×13111223221³ (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 13111223219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13111223261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6555611610 + 6555611611.

It is an arithmetic number, because the mean of its divisors is an integer number (6555611611).

Almost surely, 2^13111223221 is an apocalyptic number.

It is an amenable number.

13111223221 is a deficient number, since it is larger than the sum of its proper divisors (1).

13111223221 is an equidigital number, since it uses as much as digits as its factorization.

13111223221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 19.

Adding to 13111223221 its reverse (12232211131), we get a palindrome (25343434352).

The spelling of 13111223221 in words is "thirteen billion, one hundred eleven million, two hundred twenty-three thousand, two hundred twenty-one".