11111010221221 has 2 divisors, whose sum is σ = 11111010221222. Its totient is φ = 11111010221220.

The previous prime is 11111010221219. The next prime is 11111010221257. The reversal of 11111010221221 is 12212201011111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7282922318721 + 3828087902500 = 2698689^2 + 1956550^2 .

It is a cyclic number.

It is not a de Polignac number, because 11111010221221 - 2¹ = 11111010221219 is a prime.

Together with 11111010221219, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 11111010221195 and 11111010221204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11111010221621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5555505110610 + 5555505110611.

It is an arithmetic number, because the mean of its divisors is an integer number (5555505110611).

Almost surely, 2^{11111010221221} is an apocalyptic number.

It is an amenable number.

11111010221221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11111010221221 is an equidigital number, since it uses as much as digits as its factorization.

11111010221221 is an evil number, because the sum of its binary digits is even.

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

Adding to 11111010221221 its reverse (12212201011111), we get a palindrome (23323211232332).

The spelling of 11111010221221 in words is "eleven trillion, one hundred eleven billion, ten million, two hundred twenty-one thousand, two hundred twenty-one".