12565256761 has 2 divisors, whose sum is σ = 12565256762. Its totient is φ = 12565256760.

The previous prime is 12565256741. The next prime is 12565256779. The reversal of 12565256761 is 16765256521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6892154361 + 5673102400 = 83019^2 + 75320^2 .

It is a cyclic number.

It is not a de Polignac number, because 12565256761 - 2⁵ = 12565256729 is a prime.

It is a super-2 number, since 2×12565256761² (a number of 21 digits) contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (12565256741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6282628380 + 6282628381.

It is an arithmetic number, because the mean of its divisors is an integer number (6282628381).

Almost surely, 2^12565256761 is an apocalyptic number.

It is an amenable number.

12565256761 is a deficient number, since it is larger than the sum of its proper divisors (1).

12565256761 is an equidigital number, since it uses as much as digits as its factorization.

12565256761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 756000, while the sum is 46.

The spelling of 12565256761 in words is "twelve billion, five hundred sixty-five million, two hundred fifty-six thousand, seven hundred sixty-one".