866185205487157 has 2 divisors, whose sum is σ = 866185205487158. Its totient is φ = 866185205487156.

The previous prime is 866185205487079. The next prime is 866185205487163. The reversal of 866185205487157 is 751784502581668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 865298643889681 + 886561597476 = 29415959^2 + 941574^2 .

It is a cyclic number.

It is not a de Polignac number, because 866185205487157 - 2⁴³ = 857389112464949 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 866185205487157.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866185205487757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433092602743578 + 433092602743579.

It is an arithmetic number, because the mean of its divisors is an integer number (433092602743579).

Almost surely, 2^{866185205487157} is an apocalyptic number.

It is an amenable number.

866185205487157 is a deficient number, since it is larger than the sum of its proper divisors (1).

866185205487157 is an equidigital number, since it uses as much as digits as its factorization.

866185205487157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 903168000, while the sum is 73.

The spelling of 866185205487157 in words is "eight hundred sixty-six trillion, one hundred eighty-five billion, two hundred five million, four hundred eighty-seven thousand, one hundred fifty-seven".