121212210111 has 4 divisors (see below), whose sum is σ = 161616280152. Its totient is φ = 80808140072.

The previous prime is 121212210103. The next prime is 121212210143. The reversal of 121212210111 is 111012212121.

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: 111012212121 = 3 ⋅37004070707.

It is a cyclic number.

It is not a de Polignac number, because 121212210111 - 2³ = 121212210103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121212210191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20202035016 + ... + 20202035021.

It is an arithmetic number, because the mean of its divisors is an integer number (40404070038).

Almost surely, 2^121212210111 is an apocalyptic number.

121212210111 is a deficient number, since it is larger than the sum of its proper divisors (40404070041).

121212210111 is an equidigital number, since it uses as much as digits as its factorization.

121212210111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40404070040.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 121212210111 its reverse (111012212121), we get a palindrome (232224422232).

The spelling of 121212210111 in words is "one hundred twenty-one billion, two hundred twelve million, two hundred ten thousand, one hundred eleven".