1211232311111 has 4 divisors (see below), whose sum is σ = 1211282450400. Its totient is φ = 1211182171824.

The previous prime is 1211232311077. The next prime is 1211232311117. The reversal of 1211232311111 is 1111132321121.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211232311111 is a prime.

It is a super-2 number, since 2×1211232311111² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211232311117) 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, 25033391 + ... + 25081728.

It is an arithmetic number, because the mean of its divisors is an integer number (302820612600).

Almost surely, 2^{1211232311111} is an apocalyptic number.

1211232311111 is a deficient number, since it is larger than the sum of its proper divisors (50139289).

1211232311111 is an equidigital number, since it uses as much as digits as its factorization.

1211232311111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50139288.

The product of its digits is 72, while the sum is 20.

Adding to 1211232311111 its reverse (1111132321121), we get a palindrome (2322364632232).

The spelling of 1211232311111 in words is "one trillion, two hundred eleven billion, two hundred thirty-two million, three hundred eleven thousand, one hundred eleven".