1211243312311 has 4 divisors (see below), whose sum is σ = 1211327786824. Its totient is φ = 1211158837800.

The previous prime is 1211243312299. The next prime is 1211243312339. The reversal of 1211243312311 is 1132133421121.

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 1211243312311 - 2⁹ = 1211243311799 is a prime.

It is a super-2 number, since 2×1211243312311² (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 (1211243312341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42215745 + ... + 42244426.

It is an arithmetic number, because the mean of its divisors is an integer number (302831946706).

Almost surely, 2^{1211243312311} is an apocalyptic number.

1211243312311 is a deficient number, since it is larger than the sum of its proper divisors (84474513).

1211243312311 is an equidigital number, since it uses as much as digits as its factorization.

1211243312311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84474512.

The product of its digits is 864, while the sum is 25.

Adding to 1211243312311 its reverse (1132133421121), we get a palindrome (2343376733432).

The spelling of 1211243312311 in words is "one trillion, two hundred eleven billion, two hundred forty-three million, three hundred twelve thousand, three hundred eleven".