11211111012121 has 4 divisors (see below), whose sum is σ = 11313965241700. Its totient is φ = 11108256782544.

The previous prime is 11211111012077. The next prime is 11211111012131. The reversal of 11211111012121 is 12121011111211.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8458581156496 + 2752529855625 = 2908364^2 + 1659075^2 .

It is a cyclic number.

It is not a de Polignac number, because 11211111012121 - 2¹⁹ = 11211110487833 is a prime.

It is a super-2 number, since 2×11211111012121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11211111012095 and 11211111012104.

It is not an unprimeable number, because it can be changed into a prime (11211111012131) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51427114626 + ... + 51427114843.

It is an arithmetic number, because the mean of its divisors is an integer number (2828491310425).

Almost surely, 2^{11211111012121} is an apocalyptic number.

It is an amenable number.

11211111012121 is a deficient number, since it is larger than the sum of its proper divisors (102854229579).

11211111012121 is a wasteful number, since it uses less digits than its factorization.

11211111012121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102854229578.

The product of its (nonzero) digits is 8, while the sum is 16.

Adding to 11211111012121 its reverse (12121011111211), we get a palindrome (23332122123332).

The spelling of 11211111012121 in words is "eleven trillion, two hundred eleven billion, one hundred eleven million, twelve thousand, one hundred twenty-one".