317791987 has 2 divisors, whose sum is σ = 317791988. Its totient is φ = 317791986.

The previous prime is 317791963. The next prime is 317791997. The reversal of 317791987 is 789197713.

It is a strong prime.

It is an emirp because it is prime and its reverse (789197713) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 317791987 - 2¹¹ = 317789939 is a prime.

It is not a weakly prime, because it can be changed into another prime (317791907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 158895993 + 158895994.

It is an arithmetic number, because the mean of its divisors is an integer number (158895994).

Almost surely, 2^317791987 is an apocalyptic number.

317791987 is a deficient number, since it is larger than the sum of its proper divisors (1).

317791987 is an equidigital number, since it uses as much as digits as its factorization.

317791987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 666792, while the sum is 52.

The square root of 317791987 is about 17826.7211511259. The cubic root of 317791987 is about 682.4135592511.

The spelling of 317791987 in words is "three hundred seventeen million, seven hundred ninety-one thousand, nine hundred eighty-seven".