3131122321 has 2 divisors, whose sum is σ = 3131122322. Its totient is φ = 3131122320.

The previous prime is 3131122301. The next prime is 3131122343. The reversal of 3131122321 is 1232211313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2511112321 + 620010000 = 50111^2 + 24900^2 .

It is a cyclic number.

It is not a de Polignac number, because 3131122321 - 2¹⁷ = 3130991249 is a prime.

It is not a weakly prime, because it can be changed into another prime (3131122301) 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, 1565561160 + 1565561161.

It is an arithmetic number, because the mean of its divisors is an integer number (1565561161).

Almost surely, 2^3131122321 is an apocalyptic number.

It is an amenable number.

3131122321 is a deficient number, since it is larger than the sum of its proper divisors (1).

3131122321 is an equidigital number, since it uses as much as digits as its factorization.

3131122321 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 3131122321 is about 55956.4323469608. The cubic root of 3131122321 is about 1462.9630076238.

Adding to 3131122321 its reverse (1232211313), we get a palindrome (4363333634).

The spelling of 3131122321 in words is "three billion, one hundred thirty-one million, one hundred twenty-two thousand, three hundred twenty-one".