31211311313131 has 2 divisors, whose sum is σ = 31211311313132. Its totient is φ = 31211311313130.

The previous prime is 31211311313129. The next prime is 31211311313177. The reversal of 31211311313131 is 13131311311213.

It is a weak prime.

It is an emirp because it is prime and its reverse (13131311311213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31211311313131 - 2¹ = 31211311313129 is a prime.

It is a super-2 number, since 2×31211311313131² (a number of 28 digits) contains 22 as substring.

Together with 31211311313129, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 31211311313096 and 31211311313105.

It is not a weakly prime, because it can be changed into another prime (31211311313111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15605655656565 + 15605655656566.

It is an arithmetic number, because the mean of its divisors is an integer number (15605655656566).

Almost surely, 2^{31211311313131} is an apocalyptic number.

31211311313131 is a deficient number, since it is larger than the sum of its proper divisors (1).

31211311313131 is an equidigital number, since it uses as much as digits as its factorization.

31211311313131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 486, while the sum is 25.

Adding to 31211311313131 its reverse (13131311311213), we get a palindrome (44342622624344).

The spelling of 31211311313131 in words is "thirty-one trillion, two hundred eleven billion, three hundred eleven million, three hundred thirteen thousand, one hundred thirty-one".