1331322991 has 2 divisors, whose sum is σ = 1331322992. Its totient is φ = 1331322990.

The previous prime is 1331322929. The next prime is 1331323033. The reversal of 1331322991 is 1992231331.

It is a strong prime.

It is an emirp because it is prime and its reverse (1992231331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1331322991 - 2¹¹ = 1331320943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1331322901) 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, 665661495 + 665661496.

It is an arithmetic number, because the mean of its divisors is an integer number (665661496).

Almost surely, 2^1331322991 is an apocalyptic number.

1331322991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331322991 is an equidigital number, since it uses as much as digits as its factorization.

1331322991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 34.

The square root of 1331322991 is about 36487.2990367881. The cubic root of 1331322991 is about 1100.0889710405.

The spelling of 1331322991 in words is "one billion, three hundred thirty-one million, three hundred twenty-two thousand, nine hundred ninety-one".