1311021331 has 2 divisors, whose sum is σ = 1311021332. Its totient is φ = 1311021330.

The previous prime is 1311021329. The next prime is 1311021347. The reversal of 1311021331 is 1331201131.

It is an a-pointer prime, because the next prime (1311021347) can be obtained adding 1311021331 to its sum of digits (16).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1311021331 - 2¹ = 1311021329 is a prime.

It is a super-2 number, since 2×1311021331² = 3437553860674023122, which contains 22 as substring.

Together with 1311021329, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1311021391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655510665 + 655510666.

It is an arithmetic number, because the mean of its divisors is an integer number (655510666).

Almost surely, 2^1311021331 is an apocalyptic number.

1311021331 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311021331 is an equidigital number, since it uses as much as digits as its factorization.

1311021331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 1311021331 is about 36208.0285434046. The cubic root of 1311021331 is about 1094.4684648055.

Adding to 1311021331 its reverse (1331201131), we get a palindrome (2642222462).

The spelling of 1311021331 in words is "one billion, three hundred eleven million, twenty-one thousand, three hundred thirty-one".