1311221143 has 2 divisors, whose sum is σ = 1311221144. Its totient is φ = 1311221142.

The previous prime is 1311221111. The next prime is 1311221147. The reversal of 1311221143 is 3411221131.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1311221143 - 2⁵ = 1311221111 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1311221143.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311221147) 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 as a sum of consecutive naturals, namely, 655610571 + 655610572.

It is an arithmetic number, because the mean of its divisors is an integer number (655610572).

Almost surely, 2^1311221143 is an apocalyptic number.

1311221143 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311221143 is an equidigital number, since it uses as much as digits as its factorization.

1311221143 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 19.

The square root of 1311221143 is about 36210.7876605853. The cubic root of 1311221143 is about 1094.5240644154.

Adding to 1311221143 its reverse (3411221131), we get a palindrome (4722442274).

The spelling of 1311221143 in words is "one billion, three hundred eleven million, two hundred twenty-one thousand, one hundred forty-three".