11111211220121 has 32 divisors (see below), whose sum is σ = 11691228441600. Its totient is φ = 10547260416000.

The previous prime is 11111211220091. The next prime is 11111211220139. The reversal of 11111211220121 is 12102211211111.

It is not a de Polignac number, because 11111211220121 - 2²⁶ = 11111144111257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 11111211220121.

It is not an unprimeable number, because it can be changed into a prime (11111211220321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 207888761 + ... + 207942201.

It is an arithmetic number, because the mean of its divisors is an integer number (365350888800).

Almost surely, 2^{11111211220121} is an apocalyptic number.

It is an amenable number.

11111211220121 is a deficient number, since it is larger than the sum of its proper divisors (580017221479).

11111211220121 is a wasteful number, since it uses less digits than its factorization.

11111211220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54161.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 11111211220121 its reverse (12102211211111), we get a palindrome (23213422431232).

The spelling of 11111211220121 in words is "eleven trillion, one hundred eleven billion, two hundred eleven million, two hundred twenty thousand, one hundred twenty-one".