11111221200121 has 12 divisors (see below), whose sum is σ = 12962333388900. Its totient is φ = 9496614748320.

The previous prime is 11111221200109. The next prime is 11111221200169. The reversal of 11111221200121 is 12100212211111.

It can be written as a sum of positive squares in 2 ways, for example, as 5114653633600 + 5996567566521 = 2261560^2 + 2448789^2 .

It is not a de Polignac number, because 11111221200121 - 2⁵ = 11111221200089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11111221200095 and 11111221200104.

It is not an unprimeable number, because it can be changed into a prime (11111221204121) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 324853410 + ... + 324887611.

It is an arithmetic number, because the mean of its divisors is an integer number (1080194449075).

Almost surely, 2^{11111221200121} is an apocalyptic number.

It is an amenable number.

11111221200121 is a deficient number, since it is larger than the sum of its proper divisors (1851112188779).

11111221200121 is an equidigital number, since it uses as much as digits as its factorization.

11111221200121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649741384 (or 649741377 counting only the distinct ones).

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

Adding to 11111221200121 its reverse (12100212211111), we get a palindrome (23211433411232).

The spelling of 11111221200121 in words is "eleven trillion, one hundred eleven billion, two hundred twenty-one million, two hundred thousand, one hundred twenty-one".