31513117 has 2 divisors, whose sum is σ = 31513118. Its totient is φ = 31513116.

The previous prime is 31513091. The next prime is 31513123. The reversal of 31513117 is 71131513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22477081 + 9036036 = 4741^2 + 3006^2 .

It is an emirp because it is prime and its reverse (71131513) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31513117 - 2¹¹ = 31511069 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31513147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15756558 + 15756559.

It is an arithmetic number, because the mean of its divisors is an integer number (15756559).

Almost surely, 2^31513117 is an apocalyptic number.

It is an amenable number.

31513117 is a deficient number, since it is larger than the sum of its proper divisors (1).

31513117 is an equidigital number, since it uses as much as digits as its factorization.

31513117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 315, while the sum is 22.

The square root of 31513117 is about 5613.6545137726. The cubic root of 31513117 is about 315.8618106719.

The spelling of 31513117 in words is "thirty-one million, five hundred thirteen thousand, one hundred seventeen".