31520726317 has 2 divisors, whose sum is σ = 31520726318. Its totient is φ = 31520726316.

The previous prime is 31520726309. The next prime is 31520726327. The reversal of 31520726317 is 71362702513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23461355241 + 8059371076 = 153171^2 + 89774^2 .

It is a cyclic number.

It is not a de Polignac number, because 31520726317 - 2³ = 31520726309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31520726327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15760363158 + 15760363159.

It is an arithmetic number, because the mean of its divisors is an integer number (15760363159).

Almost surely, 2^31520726317 is an apocalyptic number.

It is an amenable number.

31520726317 is a deficient number, since it is larger than the sum of its proper divisors (1).

31520726317 is an equidigital number, since it uses as much as digits as its factorization.

31520726317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52920, while the sum is 37.

The spelling of 31520726317 in words is "thirty-one billion, five hundred twenty million, seven hundred twenty-six thousand, three hundred seventeen".