168226041821 has 2 divisors, whose sum is σ = 168226041822. Its totient is φ = 168226041820.

The previous prime is 168226041817. The next prime is 168226041839. The reversal of 168226041821 is 128140622861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153986392921 + 14239648900 = 392411^2 + 119330^2 .

It is an emirp because it is prime and its reverse (128140622861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 168226041821 - 2² = 168226041817 is a prime.

It is a super-2 number, since 2×168226041821² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168226041121) 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, 84113020910 + 84113020911.

It is an arithmetic number, because the mean of its divisors is an integer number (84113020911).

Almost surely, 2^168226041821 is an apocalyptic number.

It is an amenable number.

168226041821 is a deficient number, since it is larger than the sum of its proper divisors (1).

168226041821 is an equidigital number, since it uses as much as digits as its factorization.

168226041821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 73728, while the sum is 41.

The spelling of 168226041821 in words is "one hundred sixty-eight billion, two hundred twenty-six million, forty-one thousand, eight hundred twenty-one".