168503366621 has 2 divisors, whose sum is σ = 168503366622. Its totient is φ = 168503366620.

The previous prime is 168503366609. The next prime is 168503366623. The reversal of 168503366621 is 126663305861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 107797305625 + 60706060996 = 328325^2 + 246386^2 .

It is a cyclic number.

It is not a de Polignac number, because 168503366621 - 2¹⁸ = 168503104477 is a prime.

It is a super-2 number, since 2×168503366621² (a number of 23 digits) contains 22 as substring.

Together with 168503366623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168503366623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84251683310 + 84251683311.

It is an arithmetic number, because the mean of its divisors is an integer number (84251683311).

Almost surely, 2^168503366621 is an apocalyptic number.

It is an amenable number.

168503366621 is a deficient number, since it is larger than the sum of its proper divisors (1).

168503366621 is an equidigital number, since it uses as much as digits as its factorization.

168503366621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 933120, while the sum is 47.

The spelling of 168503366621 in words is "one hundred sixty-eight billion, five hundred three million, three hundred sixty-six thousand, six hundred twenty-one".