517666663 has 2 divisors, whose sum is σ = 517666664. Its totient is φ = 517666662.

The previous prime is 517666661. The next prime is 517666687. The reversal of 517666663 is 366666715.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 517666663 - 2¹ = 517666661 is a prime.

Together with 517666661, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (517666661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 258833331 + 258833332.

It is an arithmetic number, because the mean of its divisors is an integer number (258833332).

Almost surely, 2^517666663 is an apocalyptic number.

517666663 is a deficient number, since it is larger than the sum of its proper divisors (1).

517666663 is an equidigital number, since it uses as much as digits as its factorization.

517666663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 816480, while the sum is 46.

The square root of 517666663 is about 22752.2891815307. The cubic root of 517666663 is about 802.9405650823.

The spelling of 517666663 in words is "five hundred seventeen million, six hundred sixty-six thousand, six hundred sixty-three".