11212111121 has 4 divisors (see below), whose sum is σ = 11213471412. Its totient is φ = 11210750832.

The previous prime is 11212111087. The next prime is 11212111123. The reversal of 11212111121 is 12111121211.

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 3496948225 + 7715162896 = 59135^2 + 87836^2 .

It is a cyclic number.

It is not a de Polignac number, because 11212111121 - 2¹⁰ = 11212110097 is a prime.

It is a super-2 number, since 2×11212111121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 11212111096 and 11212111105.

It is not an unprimeable number, because it can be changed into a prime (11212111123) 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, 667706 + ... + 684291.

It is an arithmetic number, because the mean of its divisors is an integer number (2803367853).

Almost surely, 2^11212111121 is an apocalyptic number.

It is an amenable number.

11212111121 is a deficient number, since it is larger than the sum of its proper divisors (1360291).

11212111121 is an equidigital number, since it uses as much as digits as its factorization.

11212111121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1360290.

The product of its digits is 8, while the sum is 14.

Adding to 11212111121 its reverse (12111121211), we get a palindrome (23323232332).

The spelling of 11212111121 in words is "eleven billion, two hundred twelve million, one hundred eleven thousand, one hundred twenty-one".