31131020317 has 2 divisors, whose sum is σ = 31131020318. Its totient is φ = 31131020316.

The previous prime is 31131020287. The next prime is 31131020359. The reversal of 31131020317 is 71302013113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19091225241 + 12039795076 = 138171^2 + 109726^2 .

It is a cyclic number.

It is not a de Polignac number, because 31131020317 - 2⁷ = 31131020189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31138020317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15565510158 + 15565510159.

It is an arithmetic number, because the mean of its divisors is an integer number (15565510159).

Almost surely, 2^31131020317 is an apocalyptic number.

It is an amenable number.

31131020317 is a deficient number, since it is larger than the sum of its proper divisors (1).

31131020317 is an equidigital number, since it uses as much as digits as its factorization.

31131020317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 378, while the sum is 22.

The spelling of 31131020317 in words is "thirty-one billion, one hundred thirty-one million, twenty thousand, three hundred seventeen".