1211211212111 has 8 divisors (see below), whose sum is σ = 1212162338400. Its totient is φ = 1210260382560.

The previous prime is 1211211212063. The next prime is 1211211212129. The reversal of 1211211212111 is 1112121121121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1211211212111 - 2³⁰ = 1210137470287 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1211211212111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211211212011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8475710 + ... + 8617428.

It is an arithmetic number, because the mean of its divisors is an integer number (151520292300).

Almost surely, 2^{1211211212111} is an apocalyptic number.

1211211212111 is a deficient number, since it is larger than the sum of its proper divisors (951126289).

1211211212111 is a wasteful number, since it uses less digits than its factorization.

1211211212111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148369.

The product of its digits is 16, while the sum is 17.

Adding to 1211211212111 its reverse (1112121121121), we get a palindrome (2323332333232).

The spelling of 1211211212111 in words is "one trillion, two hundred eleven billion, two hundred eleven million, two hundred twelve thousand, one hundred eleven".