11011111201221 has 16 divisors (see below), whose sum is σ = 15091634001600. Its totient is φ = 7136016064128.

The previous prime is 11011111201199. The next prime is 11011111201261. The reversal of 11011111201221 is 12210211111011.

11011111201221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11011111201221 - 2⁹ = 11011111200709 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11011111201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11011111201261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43807011 + ... + 44057648.

It is an arithmetic number, because the mean of its divisors is an integer number (943227125100).

Almost surely, 2^{11011111201221} is an apocalyptic number.

It is an amenable number.

11011111201221 is a deficient number, since it is larger than the sum of its proper divisors (4080522800379).

11011111201221 is a wasteful number, since it uses less digits than its factorization.

11011111201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87865828.

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 11011111201221 its reverse (12210211111011), we get a palindrome (23221322312232).

The spelling of 11011111201221 in words is "eleven trillion, eleven billion, one hundred eleven million, two hundred one thousand, two hundred twenty-one".