491364217 has 2 divisors, whose sum is σ = 491364218. Its totient is φ = 491364216.

The previous prime is 491364173. The next prime is 491364257. The reversal of 491364217 is 712463194.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 360582121 + 130782096 = 18989^2 + 11436^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-491364217 is a prime.

It is not a weakly prime, because it can be changed into another prime (491364257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 245682108 + 245682109.

It is an arithmetic number, because the mean of its divisors is an integer number (245682109).

Almost surely, 2^491364217 is an apocalyptic number.

It is an amenable number.

491364217 is a deficient number, since it is larger than the sum of its proper divisors (1).

491364217 is an equidigital number, since it uses as much as digits as its factorization.

491364217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 37.

The square root of 491364217 is about 22166.7367242001. The cubic root of 491364217 is about 789.1044795601.

The spelling of 491364217 in words is "four hundred ninety-one million, three hundred sixty-four thousand, two hundred seventeen".