12216756581 has 2 divisors, whose sum is σ = 12216756582. Its totient is φ = 12216756580.

The previous prime is 12216756557. The next prime is 12216756583. The reversal of 12216756581 is 18565761221.

12216756581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9715256356 + 2501500225 = 98566^2 + 50015^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12216756581 is a prime.

It is a super-3 number, since 3×12216756581³ (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

Together with 12216756583, 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 (12216756583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6108378290 + 6108378291.

It is an arithmetic number, because the mean of its divisors is an integer number (6108378291).

Almost surely, 2^12216756581 is an apocalyptic number.

It is an amenable number.

12216756581 is a deficient number, since it is larger than the sum of its proper divisors (1).

12216756581 is an equidigital number, since it uses as much as digits as its factorization.

12216756581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 201600, while the sum is 44.

The spelling of 12216756581 in words is "twelve billion, two hundred sixteen million, seven hundred fifty-six thousand, five hundred eighty-one".