12565440869 has 2 divisors, whose sum is σ = 12565440870. Its totient is φ = 12565440868.

The previous prime is 12565440821. The next prime is 12565440883. The reversal of 12565440869 is 96804456521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12532802500 + 32638369 = 111950^2 + 5713^2 .

It is a cyclic number.

It is not a de Polignac number, because 12565440869 - 2³² = 8270473573 is a prime.

It is a super-2 number, since 2×12565440869² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12565440269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6282720434 + 6282720435.

It is an arithmetic number, because the mean of its divisors is an integer number (6282720435).

Almost surely, 2^12565440869 is an apocalyptic number.

It is an amenable number.

12565440869 is a deficient number, since it is larger than the sum of its proper divisors (1).

12565440869 is an equidigital number, since it uses as much as digits as its factorization.

12565440869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2073600, while the sum is 50.

The spelling of 12565440869 in words is "twelve billion, five hundred sixty-five million, four hundred forty thousand, eight hundred sixty-nine".