31513212105317 has 2 divisors, whose sum is σ = 31513212105318. Its totient is φ = 31513212105316.

The previous prime is 31513212105313. The next prime is 31513212105373. The reversal of 31513212105317 is 71350121231513.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24947887185796 + 6565324919521 = 4994786^2 + 2562289^2 .

It is a cyclic number.

It is not a de Polignac number, because 31513212105317 - 2² = 31513212105313 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31513212105313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15756606052658 + 15756606052659.

It is an arithmetic number, because the mean of its divisors is an integer number (15756606052659).

Almost surely, 2^{31513212105317} is an apocalyptic number.

It is an amenable number.

31513212105317 is a deficient number, since it is larger than the sum of its proper divisors (1).

31513212105317 is an equidigital number, since it uses as much as digits as its factorization.

31513212105317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18900, while the sum is 35.

The spelling of 31513212105317 in words is "thirty-one trillion, five hundred thirteen billion, two hundred twelve million, one hundred five thousand, three hundred seventeen".