168595122821 has 2 divisors, whose sum is σ = 168595122822. Its totient is φ = 168595122820.

The previous prime is 168595122811. The next prime is 168595122889. The reversal of 168595122821 is 128221595861.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 150272522500 + 18322600321 = 387650^2 + 135361^2 .

It is an emirp because it is prime and its reverse (128221595861) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168595122821 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 168595122821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168595122811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84297561410 + 84297561411.

It is an arithmetic number, because the mean of its divisors is an integer number (84297561411).

Almost surely, 2^168595122821 is an apocalyptic number.

It is an amenable number.

168595122821 is a deficient number, since it is larger than the sum of its proper divisors (1).

168595122821 is an equidigital number, since it uses as much as digits as its factorization.

168595122821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 691200, while the sum is 50.

The spelling of 168595122821 in words is "one hundred sixty-eight billion, five hundred ninety-five million, one hundred twenty-two thousand, eight hundred twenty-one".