311431321 has 2 divisors, whose sum is σ = 311431322. Its totient is φ = 311431320.

The previous prime is 311431297. The next prime is 311431349. The reversal of 311431321 is 123134113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 290225296 + 21206025 = 17036^2 + 4605^2 .

It is a cyclic number.

It is not a de Polignac number, because 311431321 - 2¹⁵ = 311398553 is a prime.

It is not a weakly prime, because it can be changed into another prime (311431391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155715660 + 155715661.

It is an arithmetic number, because the mean of its divisors is an integer number (155715661).

Almost surely, 2^311431321 is an apocalyptic number.

It is an amenable number.

311431321 is a deficient number, since it is larger than the sum of its proper divisors (1).

311431321 is an equidigital number, since it uses as much as digits as its factorization.

311431321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 19.

The square root of 311431321 is about 17647.4168364665. The cubic root of 311431321 is about 677.8299630447.

Adding to 311431321 its reverse (123134113), we get a palindrome (434565434).

The spelling of 311431321 in words is "three hundred eleven million, four hundred thirty-one thousand, three hundred twenty-one".