31631317 has 2 divisors, whose sum is σ = 31631318. Its totient is φ = 31631316.

The previous prime is 31631297. The next prime is 31631321. The reversal of 31631317 is 71313613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30096196 + 1535121 = 5486^2 + 1239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31631317 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31631291 and 31631300.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31631357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15815658 + 15815659.

It is an arithmetic number, because the mean of its divisors is an integer number (15815659).

Almost surely, 2^31631317 is an apocalyptic number.

It is an amenable number.

31631317 is a deficient number, since it is larger than the sum of its proper divisors (1).

31631317 is an equidigital number, since it uses as much as digits as its factorization.

31631317 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1134, while the sum is 25.

The square root of 31631317 is about 5624.1725613640. The cubic root of 31631317 is about 316.2562314488.

The spelling of 31631317 in words is "thirty-one million, six hundred thirty-one thousand, three hundred seventeen".