12121111213 has 4 divisors (see below), whose sum is σ = 12132536508. Its totient is φ = 12109685920.

The previous prime is 12121111207. The next prime is 12121111243. The reversal of 12121111213 is 31211112121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31211112121 = 7 ⋅4458730303.

It can be written as a sum of positive squares in 2 ways, for example, as 4879441609 + 7241669604 = 69853^2 + 85098^2 .

It is a cyclic number.

It is not a de Polignac number, because 12121111213 - 2¹⁷ = 12120980141 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121111243) 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, 5711056 + ... + 5713177.

It is an arithmetic number, because the mean of its divisors is an integer number (3033134127).

Almost surely, 2^12121111213 is an apocalyptic number.

It is an amenable number.

12121111213 is a deficient number, since it is larger than the sum of its proper divisors (11425295).

12121111213 is a wasteful number, since it uses less digits than its factorization.

12121111213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11425294.

The product of its digits is 24, while the sum is 16.

Adding to 12121111213 its reverse (31211112121), we get a palindrome (43332223334).

The spelling of 12121111213 in words is "twelve billion, one hundred twenty-one million, one hundred eleven thousand, two hundred thirteen".