1311331122221 has 4 divisors (see below), whose sum is σ = 1313376881244. Its totient is φ = 1309285363200.

The previous prime is 1311331122169. The next prime is 1311331122247. The reversal of 1311331122221 is 1222211331131.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1233776670025 + 77554452196 = 1110755^2 + 278486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1311331122221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311331122281) 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, 1022878550 + ... + 1022879831.

It is an arithmetic number, because the mean of its divisors is an integer number (328344220311).

Almost surely, 2^{1311331122221} is an apocalyptic number.

It is an amenable number.

1311331122221 is a deficient number, since it is larger than the sum of its proper divisors (2045759023).

1311331122221 is an equidigital number, since it uses as much as digits as its factorization.

1311331122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2045759022.

The product of its digits is 432, while the sum is 23.

Adding to 1311331122221 its reverse (1222211331131), we get a palindrome (2533542453352).

The spelling of 1311331122221 in words is "one trillion, three hundred eleven billion, three hundred thirty-one million, one hundred twenty-two thousand, two hundred twenty-one".