123111231211 has 4 divisors (see below), whose sum is σ = 123749113432. Its totient is φ = 122473348992.

The previous prime is 123111231203. The next prime is 123111231289. The reversal of 123111231211 is 112132111321.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 123111231211 - 2³ = 123111231203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (123114231211) 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 3 ways as a sum of consecutive naturals, for example, 318940821 + ... + 318941206.

It is an arithmetic number, because the mean of its divisors is an integer number (30937278358).

Almost surely, 2^123111231211 is an apocalyptic number.

123111231211 is a deficient number, since it is larger than the sum of its proper divisors (637882221).

123111231211 is an equidigital number, since it uses as much as digits as its factorization.

123111231211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637882220.

The product of its digits is 72, while the sum is 19.

Adding to 123111231211 its reverse (112132111321), we get a palindrome (235243342532).

The spelling of 123111231211 in words is "one hundred twenty-three billion, one hundred eleven million, two hundred thirty-one thousand, two hundred eleven".