12566144581 has 2 divisors, whose sum is σ = 12566144582. Its totient is φ = 12566144580.

The previous prime is 12566144579. The next prime is 12566144623. The reversal of 12566144581 is 18544166521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11840704225 + 725440356 = 108815^2 + 26934^2 .

It is an emirp because it is prime and its reverse (18544166521) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12566144581 - 2¹ = 12566144579 is a prime.

It is a super-2 number, since 2×12566144581² (a number of 21 digits) contains 22 as substring.

Together with 12566144579, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12566144561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6283072290 + 6283072291.

It is an arithmetic number, because the mean of its divisors is an integer number (6283072291).

Almost surely, 2^12566144581 is an apocalyptic number.

It is an amenable number.

12566144581 is a deficient number, since it is larger than the sum of its proper divisors (1).

12566144581 is an equidigital number, since it uses as much as digits as its factorization.

12566144581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 230400, while the sum is 43.

The spelling of 12566144581 in words is "twelve billion, five hundred sixty-six million, one hundred forty-four thousand, five hundred eighty-one".