31310120213 has 2 divisors, whose sum is σ = 31310120214. Its totient is φ = 31310120212.

The previous prime is 31310120207. The next prime is 31310120227. The reversal of 31310120213 is 31202101313.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20385271729 + 10924848484 = 142777^2 + 104522^2 .

It is a cyclic number.

It is not a de Polignac number, because 31310120213 - 2⁸ = 31310119957 is a prime.

It is a super-2 number, since 2×31310120213² (a number of 22 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31310120191 and 31310120200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31310122213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15655060106 + 15655060107.

It is an arithmetic number, because the mean of its divisors is an integer number (15655060107).

Almost surely, 2^31310120213 is an apocalyptic number.

It is an amenable number.

31310120213 is a deficient number, since it is larger than the sum of its proper divisors (1).

31310120213 is an equidigital number, since it uses as much as digits as its factorization.

31310120213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

Adding to 31310120213 its reverse (31202101313), we get a palindrome (62512221526).

The spelling of 31310120213 in words is "thirty-one billion, three hundred ten million, one hundred twenty thousand, two hundred thirteen".