8221778312081 has 2 divisors, whose sum is σ = 8221778312082. Its totient is φ = 8221778312080.

The previous prime is 8221778312053. The next prime is 8221778312203. The reversal of 8221778312081 is 1802138771228.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8216707590400 + 5070721681 = 2866480^2 + 71209^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8221778312081 is a prime.

It is a super-2 number, since 2×8221778312081² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8221778312021) 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, 4110889156040 + 4110889156041.

It is an arithmetic number, because the mean of its divisors is an integer number (4110889156041).

Almost surely, 2^{8221778312081} is an apocalyptic number.

It is an amenable number.

8221778312081 is a deficient number, since it is larger than the sum of its proper divisors (1).

8221778312081 is an equidigital number, since it uses as much as digits as its factorization.

8221778312081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 602112, while the sum is 50.

The spelling of 8221778312081 in words is "eight trillion, two hundred twenty-one billion, seven hundred seventy-eight million, three hundred twelve thousand, eighty-one".