121212111210021 has 16 divisors (see below), whose sum is σ = 193386844096320. Its totient is φ = 74592068436720.

The previous prime is 121212111209971. The next prime is 121212111210061. The reversal of 121212111210021 is 120012111212121.

It is a happy number.

It is not a de Polignac number, because 121212111210021 - 2⁹ = 121212111209509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121212111209976 and 121212111210003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121212111210061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 172666824735 + ... + 172666825436.

It is an arithmetic number, because the mean of its divisors is an integer number (12086677756020).

Almost surely, 2^{121212111210021} is an apocalyptic number.

It is an amenable number.

121212111210021 is a deficient number, since it is larger than the sum of its proper divisors (72174732886299).

121212111210021 is a wasteful number, since it uses less digits than its factorization.

121212111210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345333650193 (or 345333650187 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 121212111210021 its reverse (120012111212121), we get a palindrome (241224222422142).

The spelling of 121212111210021 in words is "one hundred twenty-one trillion, two hundred twelve billion, one hundred eleven million, two hundred ten thousand, twenty-one".