865778870477077 has 2 divisors, whose sum is σ = 865778870477078. Its totient is φ = 865778870477076.

The previous prime is 865778870477041. The next prime is 865778870477201. The reversal of 865778870477077 is 770774078877568.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 592227316589841 + 273551553887236 = 24335721^2 + 16539394^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-865778870477077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (865778870478077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432889435238538 + 432889435238539.

It is an arithmetic number, because the mean of its divisors is an integer number (432889435238539).

Almost surely, 2^{865778870477077} is an apocalyptic number.

It is an amenable number.

865778870477077 is a deficient number, since it is larger than the sum of its proper divisors (1).

865778870477077 is an equidigital number, since it uses as much as digits as its factorization.

865778870477077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 50598481920, while the sum is 88.

The spelling of 865778870477077 in words is "eight hundred sixty-five trillion, seven hundred seventy-eight billion, eight hundred seventy million, four hundred seventy-seven thousand, seventy-seven".