668182517 has 2 divisors, whose sum is σ = 668182518. Its totient is φ = 668182516.

The previous prime is 668182513. The next prime is 668182561. The reversal of 668182517 is 715281866.

It is a happy number.

It is an a-pointer prime, because the next prime (668182561) can be obtained adding 668182517 to its sum of digits (44).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 661827076 + 6355441 = 25726^2 + 2521^2 .

It is a cyclic number.

It is not a de Polignac number, because 668182517 - 2² = 668182513 is a prime.

It is equal to p_34688915 and since 668182517 and 34688915 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (668182511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334091258 + 334091259.

It is an arithmetic number, because the mean of its divisors is an integer number (334091259).

Almost surely, 2^668182517 is an apocalyptic number.

It is an amenable number.

668182517 is a deficient number, since it is larger than the sum of its proper divisors (1).

668182517 is an equidigital number, since it uses as much as digits as its factorization.

668182517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 44.

The square root of 668182517 is about 25849.2266228605. The cubic root of 668182517 is about 874.2420721598.

It can be divided in two parts, 6681 and 82517, that added together give a palindrome (89198).

The spelling of 668182517 in words is "six hundred sixty-eight million, one hundred eighty-two thousand, five hundred seventeen".