11101121121221 has 2 divisors, whose sum is σ = 11101121121222. Its totient is φ = 11101121121220.

The previous prime is 11101121121203. The next prime is 11101121121257. The reversal of 11101121121221 is 12212112110111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7504367148100 + 3596753973121 = 2739410^2 + 1896511^2 .

It is a cyclic number.

It is not a de Polignac number, because 11101121121221 - 2¹⁰ = 11101121120197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11101121121221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11101121121521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5550560560610 + 5550560560611.

It is an arithmetic number, because the mean of its divisors is an integer number (5550560560611).

Almost surely, 2^{11101121121221} is an apocalyptic number.

It is an amenable number.

11101121121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11101121121221 is an equidigital number, since it uses as much as digits as its factorization.

11101121121221 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 17.

Adding to 11101121121221 its reverse (12212112110111), we get a palindrome (23313233231332).

The spelling of 11101121121221 in words is "eleven trillion, one hundred one billion, one hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty-one".