12121221121 has 2 divisors, whose sum is σ = 12121221122. Its totient is φ = 12121221120.

The previous prime is 12121221103. The next prime is 12121221137. The reversal of 12121221121 is 12112212121.

It is an a-pointer prime, because the next prime (12121221137) can be obtained adding 12121221121 to its sum of digits (16).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11470410000 + 650811121 = 107100^2 + 25511^2 .

It is a cyclic number.

It is not a de Polignac number, because 12121221121 - 2¹¹ = 12121219073 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12121221095 and 12121221104.

It is not a weakly prime, because it can be changed into another prime (12121221521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6060610560 + 6060610561.

It is an arithmetic number, because the mean of its divisors is an integer number (6060610561).

Almost surely, 2^12121221121 is an apocalyptic number.

It is an amenable number.

12121221121 is a deficient number, since it is larger than the sum of its proper divisors (1).

12121221121 is an equidigital number, since it uses as much as digits as its factorization.

12121221121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32, while the sum is 16.

Adding to 12121221121 its reverse (12112212121), we get a palindrome (24233433242).

The spelling of 12121221121 in words is "twelve billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred twenty-one".