11101121221 has 2 divisors, whose sum is σ = 11101121222. Its totient is φ = 11101121220.

The previous prime is 11101121197. The next prime is 11101121231. The reversal of 11101121221 is 12212110111.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5698136196 + 5402985025 = 75486^2 + 73505^2 .

It is an emirp because it is prime and its reverse (12212110111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11101121221 - 2¹⁷ = 11100990149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11101121231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5550560610 + 5550560611.

It is an arithmetic number, because the mean of its divisors is an integer number (5550560611).

Almost surely, 2^11101121221 is an apocalyptic number.

It is an amenable number.

11101121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11101121221 is an equidigital number, since it uses as much as digits as its factorization.

11101121221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 11101121221 its reverse (12212110111), we get a palindrome (23313231332).

The spelling of 11101121221 in words is "eleven billion, one hundred one million, one hundred twenty-one thousand, two hundred twenty-one".