31131133321 has 2 divisors, whose sum is σ = 31131133322. Its totient is φ = 31131133320.

The previous prime is 31131133291. The next prime is 31131133331. The reversal of 31131133321 is 12333113113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21951385600 + 9179747721 = 148160^2 + 95811^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31131133321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31131133292 and 31131133301.

It is not a weakly prime, because it can be changed into another prime (31131133331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15565566660 + 15565566661.

It is an arithmetic number, because the mean of its divisors is an integer number (15565566661).

Almost surely, 2^31131133321 is an apocalyptic number.

It is an amenable number.

31131133321 is a deficient number, since it is larger than the sum of its proper divisors (1).

31131133321 is an equidigital number, since it uses as much as digits as its factorization.

31131133321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 486, while the sum is 22.

Adding to 31131133321 its reverse (12333113113), we get a palindrome (43464246434).

The spelling of 31131133321 in words is "thirty-one billion, one hundred thirty-one million, one hundred thirty-three thousand, three hundred twenty-one".