1211321331023 has 4 divisors (see below), whose sum is σ = 1211400678360. Its totient is φ = 1211241983688.

The previous prime is 1211321330983. The next prime is 1211321331041. The reversal of 1211321331023 is 3201331231121.

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 1211321331023 - 2²⁸ = 1211052895567 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 1211321331023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211321331823) 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, 39650765 + ... + 39681302.

It is an arithmetic number, because the mean of its divisors is an integer number (302850169590).

Almost surely, 2^{1211321331023} is an apocalyptic number.

1211321331023 is a deficient number, since it is larger than the sum of its proper divisors (79347337).

1211321331023 is an equidigital number, since it uses as much as digits as its factorization.

1211321331023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79347336.

The product of its (nonzero) digits is 648, while the sum is 23.

Adding to 1211321331023 its reverse (3201331231121), we get a palindrome (4412652562144).

The spelling of 1211321331023 in words is "one trillion, two hundred eleven billion, three hundred twenty-one million, three hundred thirty-one thousand, twenty-three".