866779868977709 has 2 divisors, whose sum is σ = 866779868977710. Its totient is φ = 866779868977708.

The previous prime is 866779868977663. The next prime is 866779868977721. The reversal of 866779868977709 is 907779868977668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 742079163676900 + 124700705300809 = 27241130^2 + 11166947^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866779868977709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866779868977609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433389934488854 + 433389934488855.

It is an arithmetic number, because the mean of its divisors is an integer number (433389934488855).

Almost surely, 2^{866779868977709} is an apocalyptic number.

It is an amenable number.

866779868977709 is a deficient number, since it is larger than the sum of its proper divisors (1).

866779868977709 is an equidigital number, since it uses as much as digits as its factorization.

866779868977709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1355006693376, while the sum is 104.

The spelling of 866779868977709 in words is "eight hundred sixty-six trillion, seven hundred seventy-nine billion, eight hundred sixty-eight million, nine hundred seventy-seven thousand, seven hundred nine".