865135862861 has 2 divisors, whose sum is σ = 865135862862. Its totient is φ = 865135862860.

The previous prime is 865135862779. The next prime is 865135862887. The reversal of 865135862861 is 168268531568.

It is a happy number.

865135862861 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., 538888128100 + 326247734761 = 734090^2 + 571181^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-865135862861 is a prime.

It is a super-2 number, since 2×865135862861² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 865135862861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (865135862561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432567931430 + 432567931431.

It is an arithmetic number, because the mean of its divisors is an integer number (432567931431).

Almost surely, 2^865135862861 is an apocalyptic number.

It is an amenable number.

865135862861 is a deficient number, since it is larger than the sum of its proper divisors (1).

865135862861 is an equidigital number, since it uses as much as digits as its factorization.

865135862861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16588800, while the sum is 59.

The spelling of 865135862861 in words is "eight hundred sixty-five billion, one hundred thirty-five million, eight hundred sixty-two thousand, eight hundred sixty-one".