1211331110111 has 16 divisors (see below), whose sum is σ = 1308684587040. Its totient is φ = 1117022945280.

The previous prime is 1211331110083. The next prime is 1211331110141. The reversal of 1211331110111 is 1110111331121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1211331110111 - 2²⁶ = 1211264001247 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

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 1211331110111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211331110141) 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, 2006081 + ... + 2539098.

It is an arithmetic number, because the mean of its divisors is an integer number (81792786690).

Almost surely, 2^{1211331110111} is an apocalyptic number.

1211331110111 is a deficient number, since it is larger than the sum of its proper divisors (97353476929).

1211331110111 is a wasteful number, since it uses less digits than its factorization.

1211331110111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4545514.

The product of its (nonzero) digits is 18, while the sum is 17.

Adding to 1211331110111 its reverse (1110111331121), we get a palindrome (2321442441232).

The spelling of 1211331110111 in words is "one trillion, two hundred eleven billion, three hundred thirty-one million, one hundred ten thousand, one hundred eleven".